Teenage Mutant Ninja Turtles: Heroes in a Hard-Shell

Teenage Mutant Ninja Turtles: Heroes in a Hard-Shell is a 2D-animated action-comedy-drama series based on the hit underground comic Eastman & Laird's TEENAGE MUTANT NINJA TURTLES, as well as its many incarnations. It is currently running as a fan-fiction at: https://archiveofourown.org/works/14127303, as well as on the author's DeviantART gallery: TailsandSpike4EX, and on FanFiction.Net under the author named Scrappy Doo Fan. They all go under the same name, but on DA, the chapters will be posted separately and not as frequently.

The series is rated TV-PG.

Synopsis
15 years ago on June 9, 1992, the recently-married HAMATO YOSHI and TANG SHEN had just moved from Japan to MANHATTAN, where they purchased 5 baby turtles from a pet shop. But due to an incidental encounter with a pet-store cat & rat, as well as a fight with some thugs in a pet store, they were all doused in a strange purple goop which transformed them into the animals that they respectively came in contact with...not to mention, it caused the quintet of tiny turtles to gain human qualities and traits. 15 years later in 2007, the 5 tiny turtle-tots have become five unusual turtle teens. At the helm is LEONARDO, the bold, self-proclaimed leader; the technologically-gifted and diplomatic DONATELLO; the short-tempered and wisecracking RAPHAEL; easygoing, adventurous MICHELANGELO; and meek, curious, & self-conscious VENUS DeMILO. The team ventures to the surface, only to end up coming to the rescue when the notorious Purple Dragons street gang threatens the city. But is there something (or someone) more fiendish pulling the strings?

The series draws inspiration from:
 * the original 1984 underground comic books, & the series that followed it
 * the 1987-1996 Murakami-Wolf-Swenson/Fred Wolf Films cartoon series
 * Teenage Mutant Ninja Turtles Adventures, the comic series published by Archie Comics, and the Mighty Mutanimals comic spin-off
 * the short-lived live-action FOX Kids TV series
 * the 2003-'08 4Kids cartoon (excluding Turtles Forever)
 * the currently-running IDW comic series
 * the 2-part 1996 Japanese OVA (Mutant Turtles: Chojin Densetsu-Hen)
 * the 2012-2017 CGI Nickelodeon animated series
 * the 2018/2019 currently-running (at the time I wrote this) Nickelodeon series
 * the first 2 live-action films with costumes done by Jim Henson's Creature Shop...and maybe SOME ideas from the cruddy 3rd movie
 * the 4th, CGI-animated movie from 2007
 * the 2014-'16 live-action film duology
 * the 1989 NES game
 * the Turtles in Time video-game
 * the Game Boy trilogy:
 * Fall of the Foot Clan
 * Back from the Sewers
 * Radical Rescue
 * The Hyperstone Heist
 * Tournament Fighters
 * The Manhattan Missions
 * The Image Comics run (some concepts & characters)
 * TMNT: Odyssey, the fanmade comic which acts as an unofficial conclusion to the Mirage Studios era of TMNT.

Seasons and sagas

 * Season One: The Krang Arc
 * 2-Part Pilot: Heroes in a Hard-Shell
 * 2-Part Special #1: Operation Neutrinos
 * 2-Part Special #2: Turtles in Time
 * 3-Part Special: The Turtles vs. H.A.V.O.C.
 * 2-Part Season 1 Finale: The Wrath of Krang
 * Season 2: The Shredder Arc
 * Season Two, Part 1: The Foot Clan/Mutation Mania Sagas
 * Season Two, Part 2: Turtles in Space Saga
 * Season Two, Part 3: Battle for New York Saga


 * Full-Length Movie Special 1: Turtles Forever: Re-Shelled
 * Movie Special #2: 
 * Full-Length Special: Bebop and Rocksteady Save the Universe! (takes place before Season 3)
 * DTV Movie: City at War: The Movie (stand-alone film)


 * Season 3: The Dragon Lord Arc
 * Part 1: The Sho-Kanabo Saga
 * Part 2: The Ninja Tribunal Saga
 * 5-Part Special: The Wrath of Ch'rell (series finale)

Crossover specials/comics

 * Heroes in a Hard-Shell, Pt. 3: Newtralized! (with Spider-Man)
 * Kavaxas Attacks! (with The Real/Extreme Ghostbusters)
 * Turtles Forever: Re-Shelled (with TMNT 1984, 1987/Archie, 2003, IDW, 1996 OVA, 1990/2007, 2012, 2018)
 * Mutants of the Universe (with the 2002 He-Man and the Masters of the Universe cartoon)
 * Turtle Recall (with Rise of the Teenage Mutant Ninja Turtles)

Japanese voice cast
This page is already under construction at the moment.

List of Episodes
The episode list is currently under construction, though Season 1's list is completed.

The Hamato-Kame Clan

 * Leonardo Kinzo 'Leo' Splinterson (Benjamin Diskin [English], Koichi Yamadera [Japanese]): Considered the eldest sibling (though he only hatched a few seconds earlier than his siblings) and leader of the team, he is distinguished by his blue mask and being a darker shade of green than his siblings. His signature weapons are a pair of ninjato (which he mistakenly refers to as katanas). Leonardo is driven, takes his training seriously and even in his spare time doesn't neglect his training—though he tends to be angry when his siblings do not take things as seriously. However, he bears the burden of having his siblings' lives in his hands, and his duties as a leader take a toll on him (the reason why he watches a cartoon called  "Mega-Bot: The Cosmic Defender " is to relax and take a load off his shoulders), and he takes it really hard whenever the team suffers a setback. He is considered the best fighter of the five due to his training, but he truly sets himself apart due to his skills and strategy.
 * Donatello Bardi 'Don' Splinterson (Charlie Schlatter [regular] and Phil LaMarr [alternate], Toshio Furukawa [Japanese]): Donatello (or “Don” by Zach) is the brains of the team, slightly-taller than his siblings and clad in a purple mask, goggles optional. Despite his fighting skills being on-par with his siblings, Don’s true power lies in his brilliant scientific mind, able to construct complex machinery and gadgets from discarded materials for his family to use and save the day with. Despite his intelligence, he’s not very good at improvising and loses his cool whenever things go wrong, and since he’s more of a builder than a strategic thinker he lets Leo be leader. He takes great pride in his inventions and yearns for recognition. He is also a firm believer in scientific possibilities and doesn’t exactly hold well together when confronted with the supernatural. Out of the entire team, he’s the most socially-awkward, especially around April’s friend Irma, on whom he has a massive crush.
 * Raphael Firenzo 'Raph' Splinterson/The Nightwatcher (Curtis Armstrong [English], Toru Furuya [Japanese]): Clad in a red mask and a hot-blooded attitude, Raphael is the second-in-command of the team. He is hotheaded, temperamental, and sarcastic, which allows enemies to take advantage of his anger many times and (as usual) clash with the more levelheaded Leo. He’s prone to storming off in a huff, but usually he always comes back and reconciles with his siblings, because even though he gives them a hard time, he does love his friends and family very much. He acts tough and grouchy (typical New York attitude), but in actuality he is quite insecure, believing that humanity will only see them as “freaks” and “monsters”. He’s not ignorant of his flaws, and despite being “very cool but rude” (his words, not mine...sorta), he has gained better control over his temper. Raph is the only one of the Turtles who is almost on par with Leo in terms of fighting skills. Physically the strongest and most violent out of all 4 Turtles, he sometimes trades technique for brute force, making his moves effective but flawed. Despite his snark, rudeness and temper, Raph is a loyal ally and once someone manages to prove themselves to him he considers them a friend...though for some, it takes a while for him to warm up to, though it’s more out of worry than actual malice.
 * Michelangelo Buonaroti "Mikey" Splinterson/The Turtle Titan (Jaleel White [regular], Kyle Massey [alternate], Kappei Yamaguchi [Japanese]): Fun-loving, adventurous, and laid-back, Mikey is the self-proclaimed “wild and crazy” Turtle, and he knows it. Mikey is considered to be the youngest sibling of the team. Despite being skilled enough to keep up with his siblings, he prefers to slack off, although he knows when to be serious. He may appear less intelligent than his siblings, but it’s more due to childlike naivete and a playful outlook on life than genuine idiocy. Plus, he’s smarter than he lets on, often surprising his friends and siblings with hidden bouts of intelligence, but due to his chill demeanor, he prefers to let others like Leo and Don do the heavy thinking. He has a chill, surfer-dude like attitude and is the only one who keeps his cool in most situations, as well as the first of the Turtles to befriend Zach. Mike happens to be a bit of a flirt with the ladies, but that’s only because he’s always wanted a girlfriend...which leads to him being manipulated by some of the team’s female foes....and later, leads to him and April falling for one another. Though he can be a bit slow on the uptake, his optimism and heart never fail to lift the spirits of his family and friends, and he’s considered the heart of the team. He loves making wisecracks and snarky comments in battle to trip up his enemies and irritate them. After his pet cat Klunk passed away on his 8th birthday, he started a pirate radio broadcast called "Shell Power" that he runs sporadically from time-to-time.
 * Venus Artemsia "Venny" de Milo Splinterson (Cathy Cavadini [English], Aya Hirano [Japanese]): Venus is the youngest (by 2 minutes), most cautious, and the clumsiest of the Turtles, though it's suspected that this is a ruse to lure her opponents into a false sense of confidence and let their guard down. She is sweet and kind to her friends, but in battle she is a savage, lethal fighter. She enjoys listening to J-pop music, dreaming of starting her own J-pop group someday. She later develops a crush on the hulking mutant turtle Slash, being the only one who sees him as a kind-hearted, misunderstood soul who only seeks acceptance. Despite being the youngest, she acts as a big-sister to the team (especially when Leon is wallowing in his own self-pity), since her cautiousness is mostly because she wants to keep her brothers from getting killed. She has a great interest in classic literature, mostly the works of Ray Bradbury.
 * Hamato Yoshi/Master Splinter (Greg Baldwin [pilot episode, Shell-Shocked video game, and multi-part specials], Sab Shimono [regular], Shozo Iizuka [Japanese]): Since he became a rat-man, Splinter has raised the Turtles as his own kids, alongside Tang Shen, as well as teaching them the art of Ninjutsu, in the hopes that if they ever came face-to-face with an evil like Shredder, they would at least be able to take him on. While he is a loving father, he is also a stern yet wise and caring sensei. He is sometimes enigmatic, but it’s only so the Turtles will figure things out for themselves since that’s the only way to learn things. Being overprotective of his children, he was reluctant to let them venture to the surface on their own, but expressed great pride upon learning that they are able to handle it. He secretly fears that someday his children will no longer need him, though no matter what, they’ll always need him as a dad. He keeps in touch with his paternal cousin, Hamato Takeshi.
 * Tang Shen/Master Whisker (Julia Kato [English, TV series], Nicole Oliver [English, videogames], Mami Koyama [Japanese]): A Chinese woman who is Hamato Yoshi’s childhood sweetheart, and later became his wife. She loves nature, so she decided to include a turtle pond in the backyard of their home, which led to the purchase of the 5 baby turtles. She and Yoshi considered having children, but Tang Shen was sterile, which is why they consider the Turtles their children. She also aids Splinter in training their children, whom all refer to her as “mother” (though Mike used to call her “mommy” before switching to “mom” when he turned seven). In a twist of irony, while Yoshi was mutated into a humanoid rat, Tang Shen was mutated into a humanoid cat. It hasn't affected their love for each other, though.
 * April Harriet O'Neil (Nika Futterman [Heroes in a Hard-Shell/English, some S1 episodes], Alana Ubach [TMNT film retellings/Future], Susan Egan [Season 2/English], E.G. Daily [Season 3/English], Satomi Sato [Japanese]): A 16-year-old (for Season 1 only) prodigy stuck in normal high school (due to her mom's financial problems), where she is in a rut, bored beyond belief, and she, her adopted brother Zach, and her mother live in a small apartment. She and Zach were saved by the Turtles when the Purple Dragons tried to mug (& possibly violate) her, and since then she has been close friends with them, helping them adjust to the world and help them in their endeavors, all while gaining a lot of excitement in her life. Out of all the Turtles, she has become the closest to Mike, actually gaining a crush on him, & beginning her kunoichi training so she can battle alongside the Hamato-Kame Clan. Needless to say, April had much growing-up to do in a short time due to the looming threat of Krang, but still manages to hold her own against more experienced fighters.
 * Zachary “Zach” Allen-O’Neil (voiced by Drake Flynn [English], Takeshi Kusao [Japanese]): April’s 12-year-old adoptive brother who’s always got a question on his mind and a precocious crush on a girl who’s older than him. His estranged father, Dr. Chet Allen, was killed by the notorious Purple Dragon street gang when he was only four. Since then, he was taken in by April and her mother. He likes to act older than he actually is, attempting to flirt with girls he gets crushes on and sneaking along on the Turtles' missions in order to prove his worth to them. Ironically enough, the Neutrinos' teenage princess, Trib, gains a crush on him after he ends up saving her from General Traag, though Zach already has a crush on his classmate, Renet Tilley.

Allies and annoyances

 * Angel Bridge (Breanna Yde [regular], Cree Summer [alternate], Mayumi Tanaka [Japanese]): A rough-and-tumble, sarcastic, feisty 12-year-old tomboy whose (widowed) father adopted the kid who would soon become the street vigilante Casey Jones, Angel rarely takes crap from anybody. She frequently targets Zach as the main victim of her many pranks (ever since they were in Pre-K), but it's only because she has a massive crush on him. However, Zach isn't exactly willing to forgive her so easily...
 * Arnold Bernard "Casey" Jones, Jr. (Travis Willingham, Jaxon Mercey as 8-year-old Arnold, Ryusei Nakao [Japanese]): A plucky teenage boy who moonlights as a hockey mask-wearing street vigilante fighting crime using sports equipment. His father and namesake died in a pet-shop fire started by the Purple Dragons when he refused to pay "protection money". After being stuck in an orphanage with his older sister Tiffany, he was adopted by the Bridge family. Despite his new family treating him well, he was left with a great deal of anger and frustration. He tried to vent it by joining the school's hockey team but he was kicked off for his recklessness and aggression, which wasn't helped by his sister's boyfriend, Burne, constantly looking down on and making fun of him. Instead he turned his skills towards vigilantism, not simply limiting his beatings to members of the Purple Dragons, but attacking anyone who committed a crime, no matter how minor. When he first met the Turtles, his temper was so out-of-control he even made Raphael look calm, but the Turtles and April managed to hold him back and convince him to no longer act in anger, but for justice. After that Casey became a lot calmer, and an ally of the turtles. His thick-headed attitude gets him into problems, but his heart's always in the right spot. Despite not being as smart as the likes of April and Donatello, he has 'street smarts' and can think quickly on his feet. He has a crush on fellow student, and local granola-girl Gabrielle "Gabby" Johansen....and maybe one on Raph, so he's probably bisexual.
 * Tiffany Jones (Grey Griffin): Casey's older sister and Burne Thompson's former girlfriend. She's a bit mean towards her brother Casey, but not overly mean. Tiffany does not approve of her brother being friends with the Teenage Mutant Ninja Turtles, as she has a fear of turtles (since Casey apparently put one in her bed when he was 4 and she was 6). She used to date Burne Thompson, since both she and Burne despise the Ninja Turtles, but she dumped him once Burne bought mock turtle soup for her lunch. Even though Tiffany is chelonaphobic (afraid of turtles), she's against the idea of killing turtles, let alone eating them.
 * "Blazin' Burne" Thompson (Sam Marin, Thomas F. Wilson [future self]): A jock at April's school who regularly bullies April, Irma and Casey, though he’s an arrogant meathead who’s all bark and no bite. He usually likes to brag to his ex-girlfriend Tiffany about how awesome he thinks he is, though he is easily outfoxed. He is the show's equivalent of the recurring Power Rangers character Farkas "Bulk" Bulkmeyer.
 * Vernon "Vern" Fenwick (Tom Kenny): Burne's nerdy, sycophantic, right-hand man who often does his homework and classwork for him. He sees Burne as his friend, even if he doesn't realize Burne mostly keeps him around so he can slack off. He is the show's equivalent of the recurring Power Rangers character Eugene "Skull" Skullovitch.
 * Irma Langenstein (Kimberly Brooks [English, regular], Maggie Blue O'Hara [English, alternate], Ami Koshimizu [Japanese]): April’s best friend and a member of the school’s Newspaper Club, she naturally became curious about the mysterious green crime fighters who saved April and Zach, so she decided to investigate. She trailed the two from behind, only to come upon the Turtles’ subway lair. At first she was terrified of them, but Don attempted to quell her fears. Learning that there was someone who shared her interests, Irma and Donatello quickly became friends—and maybe more someday...
 * Candace "Candy" Fine (Eileen Stevens): A friend of April, Irma, & Casey, as well as the girlfriend of Ricky Caballos, the boy who would become Mondo Gecko. Unlike Mondo's parents, Candy and her parents actually take Mondo's mutation well, welcoming him to stay with open arms.
 * Howard "Howie" Hardy (Drake Bell): A good friend of Irma and a musician. He's the keyboardist and lead singer of his indie rock band, The Booyakashas, & a former member of the Purple Dragons who was once arrested by his father, who's an NYPD officer. The Ninja Turtles (especially Don, though that might just be because he's in love with Irma) don't like Howie for being a part of the Purple Dragons despite him reforming, and they don't like his band's music.
 * Landor and Merrick Tilley (David Duchovny [Landor] and Gillian Anderson [Merrick]): Two members of the Time Travel Council, and Krakus & Renet's mom and dad.
 * Krakus Tilley (Kevin Conroy): A member of the Time Travel Council, a time-cop, and Renet's older brother; he ventured back in time to capture Titanus and prevent a great calamity that would destroy the world as we know it.
 * Cudley the Cow-Lick (Michael Luna): A trans-dimensional entity who happens to look exactly like a disembodied, floating cow's head. He is the official means of transport for the Stump Intergalactic Wrestling Federation (SIWF), and is inadvertently responsible for the formation of the team known as the Mighty Mutanimals. He is quite jovial and generally means no harm, although his only method of transport is carrying his passengers in his mouth, which usually leaves them covered in his saliva.
 * Veronica 'Ronnie' O'Neil (Stephanie Lemelin [Heroes in a Hard-Shell, Parts 2 and 3], Renae Jacobs [subsequent appearances in series]): April’s mother & a reporter for Channel 6. Due to not having recently made any reports of value, however, she, her second-born daughter, and adoptive son have money problems, & must live in a small apartment. However, when the turtles made their first appearance and saved her from the Purple Dragons, she became one of their informants and allies. After that it was several of her well-received reports and articles that helped the people accept the Turtles and the other heroic mutants and through her actions, bring eventually bring them together in a community. After that she was promoted to anchorwoman, reporting the news live on Channel 6, and money was no longer an issue at that point. Since then she has gotten along rather well with the turtles, and since April & Zach see them as future brothers-in-law, she has tried to be something of a mother figure for them, and a future mom-in-law towards Mike, even spending time with Tang Shen.
 * The Neutrino Rebel Force - a coalition of young Neutrinos, as well as other Dimension X species, who have banded together to put a stop to the warlike conquest of Krang and his Rock Soldiers. The 3 mentioned below volunteered to venture to Earth in order to recruit the aid of the "shell-backed warriors" who dared to make Krang look foolish.
 * Zakko (Bruce Dinsmore): A purple-haired, sunglasses-clad male Neutrino, and the default leader of the Rebel Force. He is also a prison guard in Dimension X.
 * Dask (Rob Tinkler): A blue-and-spiky-haired yellow-clad male Neutrino, and the second-in-command of the Rebel Force. He is also a Dimension X prison guard.
 * Kala (Bryn McAuley): An orange-haired, green-clad, female Neutrino, and the 3rd-in-command of the Rebel Force. She was originally a member of the Neutrinos' Royal Guard (and Princess Trib's best friend) before Krang launched his coup d'etat; following this, she decided to train any new recruits for the rebel forces, as well as acting as a combat leader.
 * Sgt. Bananas (Mike Judge): A militaristic mutant gorilla who helps to train the Neutrino Rebel Force recruits; he was originally an ordinary Earth gorilla mutated by Bezerko to act as Krang's drill sergeant, but Bananas soon learned of Krang's evil intentions and rebelled against him, joining the Neutrino forces.
 * Alim "Major Merdude" Coelacanth (Jeff Bennett in a French accent): A hot-tempered "fin-ja" (ninja of the ocean) clad in an eyepatch and wielding a sharp trident, with the ability to control water itself.
 * Princess "Trib" Tribble (Maryke Hendrikse): The teenage daughter of King Zentor and Queen Grisla, she is bold and headstrong, especially refusing to surrender to General Traag after his Rock Soldiers storm their home planet of Neutrinus-8. She eventually gains a crush on Zach after he saves her from Gen. Traag and Lt. Granitor.
 * Kris-Mu (Stephanie Sheh): The kindhearted fairy guardian of the Muta-Stones, and the Neutrinos' patron deity, as well as the sister of Dark-Mu, guardian of the Dark Muta-Stones.
 * Baxter Kenneth Stockman (Nat Faxon): A timid, bashful scientist and an ally of the Ninja Turtles. When he unveiled his latest invention, the MOUSERS, which he claimed would help keep Manhattan's rat population under control, he was soon targeted by the Rat King, so the Turtles had to act as his bodyguards. But eventually, when they were overwhelmed by the swarms of rodents, Baxter overcame his timid nature and unleashed a Mega-Mouser robot, which managed to help the Turtles send the Rat King packing. Afterwards, he would become their main technical consultant and would aid them whenever he could.
 * Mr. Murakami (Greg Baldwin): A blind chef who owns a Japanese restaurant. Despite his blindness, he knows what the turtles are due to his other senses. Ever since the turtles saved his restaurant from the purple dragons he has become a good friend, often cooking for them. He invented 'pizza potstickers'--dumplings filled with pizza ingredients, which the turtles love.
 * Keno Murakami (Dante Basco): Mr. Murakami's hot-blooded young nephew; he knows that the Turtles exist, but has decided that as long as his uncle likes them, then they're alright. He knows some martial arts, but at least enough to defend himself in a one-on-one fight.
 * The Mighty Mutanimals: A group of mutants (some of whom used to be humans) who fight for the rights of mutant-kind and act as the Turtles' backup team when they can't be around to handle a situation.
 * Leatherhead (Brad Garrett, imitating the late Len Carlson with a Cajun accent): An alligator born in Louisiana who was once an exotic pet, kept and raised as an egg by a kindly young boy named Jess Harley until his cruel parents flushed him down the sewer when he was still small. He came into contact with some mutagen and transformed into the humanoid alligator he currently is. Taken in and raised by kindly Utroms, they tutored him in various scientific fields. He and Ace first encountered the Turtles when they were on the run from Simon Bonesteel, though Leatherhead vowed that if any harm came to Ace, he'd "make gumbo outta their flesh, and use their bones for spoons, you betcha". He and Ace befriended the Turtles and became inspired to start a group dedicated to fighting evil (the Mighty Mutanimals).
 * Ace Duck (Terry McGovern): A hot-blooded mutant duck who's no slouch when it comes to flying vehicles. Originally a normal mallard, he was mutated by a mutagen spill during one of Chaplin's mutagen field tests, and waddled into the sewers, where he first encountered Leatherhead, who took him to the Utroms, who trained him to be a combat pilot. He and Leatherhead befriended the Turtles and helped them defeat Bonesteel, which would soon result in them becoming the co-founders of the Mighty Mutanimals.
 * Slash (Jim J. Cummings): Originally a turtle from the same pet shop as the Turtles, he was stolen by the Purple Dragon gang member who would soon be known as Bebop, who secretly raised him. However, when Shredder and Krang decided that the only way to beat mutant turtles was with a mutant turtle of their own, Slash was exposed to imperfect mutagen, which transformed him into a behemoth of a mutant turtle, similar to our beloved green teens, but childlike and feral. The other Turtles were more than willing to take Slash down, but Venus saw that Slash wasn't evil—he was just like a lost child, scared and angry at the world. She later gave him perfected mutagen, which made him fully intelligent, as well as sapient, though he knew he still had much to learn, and left with Leatherhead and Ace, who both vowed to help teach him; he later returned during the Northampton Arc after Raphael was drained of his mutagen by a transformed leech, and was willing to help his future brother-in-law reclaim his mutation.
 * Ricky Caballos/Mondo Gecko (Michael Jones): A young skateboarder who was exposed to mutagen through one of Ch'rell's experiments; due to him carrying his pet gecko Lars, he mutated into a human-sized humanoid gecko, and as a result he was rejected and cast onto the streets by his parents. Sad, lonely and vulnerable, he was taken in by a feline crime boss called "Scratch" who took advantage of his mutant powers for his own ends. He befriended Michelangelo, who helped him realize that he was being used and turned on Scratch. After this, he would become a founding member of the Mutanimals, and was taken in by Candy's parents. Similar to Mike, he is fun-loving and laid-back, but is also emotionally vulnerable, especially because he has abandonment issues, and as such, gets nervous when he is left alone.
 * Wingnut (Andy Berman): A bat-like alien from the planet Huanu; Wingnut enjoyed exploring with his best friend Screwloose, but when they returned to visit their home world, it was destroyed by Krang. This drove Wingnut into a frenzied fury, and he & Screwloose swore vengeance on Krang, vowing to sniff him out and make him face the consequences of his actions. He and Screwloose first met and befriended Michelangelo, who helped them realize that seeking vengeance would make them as bad as Krang. He and Screwloose became members of the Mutanimals during the Turtles in Space arc, and would aid their fellow allies in battling Dregg's forces when they came to Earth.
 * Screwloose (Dave Foley): A mosquito-like alien from Huanu, and Wingnut's lifelong best friend who traveled with him throughout the galaxy, and joined him in seeking vengeance on Krang after the destruction of Huanu.
 * Pete (Bobcat Goldthwait): A shaky, neurotic mutant pigeon who lives in Mutantropolis; he is one of the few who is suspicious of Old Hob and Titanus, but is willing to help April and Zach uncover the truth. He'd later join the Mighty Mutanimals group during the Turtles' space adventure.
 * Miyamoto Usagi/Rabbit Ronin (Eric J. Vale): An anthropomorphic rabbit samurai who accidentally got transported to the Turtles’ world after a failed dimensional portal experiment by Ch’rell and Krang. Being weary of ninja due to having a bad reputation in his world, he first fought the turtles, but befriended them soon afterwards; though Donatello couldn't fix the dimensional portal, Usagi accepted his fate and decided that he might as well adapt to his new surroundings. As a born samurai, he is loyal and very honorable, as well as being very brave and have a great sense of justice.  He is paired with twin katana and has a close friendship with the fellow honorable warrior Leonardo, as well as being a member of the Mighty Mutanimals. He sometimes serves as a father figure to Mondo, who aspires to be as brave & fearless a hero as he is.
 * Jagwar (James C. Mathis III): A half-human, half-jaguar hybrid due to his lineage—apparently his mother mated with a humanoid jaguar spirit (long story,) though his jaguar traits only came to light after he turned twelve. During the time where the Turtles were absent from New York, he was captured by Kraangborgs and taken to TGRI's Manhattan facilities, where he was rescued by and joined the Mutanimals.
 * Dr. Jack Finney/Ray Fillet (Rodger Bumpass): Formerly a marine biologist who worked at the Brooklyn Aquarium, he was transformed into a mutant manta when he came in contact with one of the aquarium's mantas before he left, and was shortly after splashed in mutagen by Bebop and Rocksteady, who were dumping out some of the mutagen before they came up with the idea to sell it as an energy drink. He later joined the Mutanimals as one of its founding members.
 * Bubbla the Glublub (Howie Mandel): A pint-size humanoid mutant sea creature that has the claws of a lobster, the body of a goldfish, and the lure of an angler-fish on his head--he's also 5% prawn, but nobody's quite certain where it shows; he was found by Dr. Finney after his mutation, and taught him how to adapt to his new form.
 * Gulliver Steinbeck (Patton Oswalt): An anthropomorphic mutant seagull who was transformed by Bebop and Rocksteady's "Muta-Might Energy Drink" (a previous moneymaking scheme of theirs that backfired). He acts as an informant for the Turtles, living on a houseboat he owns at the docks, which the Mutanimals have since converted into a boat-mobile that can travel on land.
 * Queequeg/Warrior Walrus (Jason Harris): A mutant walrus who was once an ordinary walrus that washed up ashore on the beaches of Coney Island after coming in contact with the spilled mutagen. Dr. Ray Fillet soon discovered him and brought him back to the aquarium to nurse him back to health, naming him after his favorite character from the novel Moby Dick, and Dr. Fillet's presence caused him to mutate into a humanoid form, while still retaining his walrus traits.
 * Caitlyn Munroe/Alopex (Meagan Smith): Formerly a goth girl from Zach's school, Robert F. Wagner Middle School, she was taken by the Purple Dragons and mutated into an arctic fox during Krang’s experiments. As a human, she had a habit of standing up to Angel whenever she was picking on Zach. Unlike the turtles, in terms of age and behavior she acts more like a preteen and is a bit more immature. She is snarky with something of a rebellious streak but she would go to great lengths to protect her friends. She doesn't wear a mask but she has applied face paint around her eyes, choosing a lilac hue. Though not as physically powerful, she has speed and agility beyond that of any turtle or human. She doesn't fight with any weapons but uses her claws and fangs in combat. She joins the Mighty Mutanimals, and later gets a crush on Wingnut.
 * Marianna (Colleen Villard): A mutant flying-fox bat who also lives in Mutantropolis, and has a crush on Screwloose.
 * Dr. Tristan Rockwell/Monkey Brainz (Tom Kane): A scientist who was mutated into a tall, lanky primate that is an amalgam of several simian species (though the most dominant traits are his monkey tail and his chimp-like body); he fights using his long limbs to leapfrog away from his foes, as well as using banana grenades to briefly blind them and using the peels to make them slip up afterwards.
 * Herman the Hermit Crab (Terry Klassen): A mutated hermit crab with a cybernetic claw who is a member of the Mutanimals. He acts as the tank, as well as a purveyor of heavy weaponry.
 * Daniel Loggia/Squidweight (Tom Kenny): An athlete who was one of Casey's good friends who was mutated into a blue skinned jellyfish/arrowhead squid hybrid after touching a squid and got stung by a jellyfish during an incident when he was on a field trip to the Brooklyn Aquarium. Now he became a new member of the Mighty Mutanimals and has stinging tentacles and wields a throwing hammer as a weapon.
 * Richard Jones/Sloth Jockey (Carlos Alarazqui): A skateboarder who was Mondo Gecko's best friend and partner who got exposed to the mutagen due to a zoo incident; he was mutated into a humanoid sloth and turned to a life of crime. He went on a spree of stealing food from humans which caught the attention to the Turtles who fought him until Mondo Gecko recognized him as a mutant and they reunited and in return he offered a spot to join the Mighty Mutanimals.
 * Chuck Hamill/Camo-Shark (Andrew Francis): A mutated wobbegong shark who is a new member of the Mutanimals. He was one of April's good friends, as well as a member of the school's swim team as well as the fisherman who got mutated into a humanoid shark which gave the ability to turn himself invisible. He wields an anchor as a weapon.
 * The Punk Frogs: A quartet of former homeless people who were mutated into amphibian warriors thanks to the Garbageman, they were taken in by Mr. Murakami and act as his restaurant's bodyguards....as well as reserve members of the Mutanimals.
 * Napoleon Bonafrog (Matthew Lillard): A mutant frog who wields a bullwhip, Indiana Jones-style.
 * Genghis Croak (Arsenio Hall): A mutant frog who wields a battleaxe and dresses in Viking-style clothing.
 * Attila the Hop (Jason Marsden): A mutant frog who wields a morning-star.
 * Rasputin the Mad-Frog (Rino Romano): A mutant frog who wields a bow and trick-arrows, Robin Hood/Green Arrow-style.
 * The Silver Sentry/Kenneth Clutch (Phil LaMarr): A member of the Justice Force (the TMNT world's version of the JLA) who is an analog of Superman.
 * Peter B. Parker/Spider-Man (Josh Keaton): A student at Midtown High who gained the abilities of multiple spiders after being bitten by a genetically-altered ( not radioactive) spider during a field trip; he occasionally works with the Ninja Turtles from time to time.
 * The Ninja Tribunal: A group of four (formerly 5) ninjutsu masters who recruit the Ninja Turtles and four other humans as acolytes to combat an unspecified threat.
 * Kon-Shisho (Fred Willard): The Ninja Master of Spirit; Kon's belief in the greater good along with his immortality has resulted in him seeing mortal beings as merely pawns in a greater game. Because of this Master Splinter considers him heartless and no better than the Shredder or his heralds. Kon also shows considerable arrogance, never considering that his judgement could be wrong and this arrogance also causes him to underestimate the Shredder's powerful heralds.
 * Juto-Shisho (Mark Acheson): The Ninja Master of Weapons; Juto is callous and shows disregard for his acolytes safety and well-being, caring more about the threat of the Dragon Shredder. Upon being told of Chu-Hsi's death, he heartlessly dismisses it as something that "must be", showing no remorse for the man's death or even taking responsibility for the fact that it was partially his fault. Due to his immortality, Juto developed the belief that mortals were of no significance in the greater scheme of things.
 * Chikara-Shisho (Sonja Ball): The Ninja Master of Strength, and the only female member of the Tribunal; She is short tempered and shows hatred for weakness and sloppy work but congratulates strength and hard effort. Chikara's immortality has also deteriorated her sense of compassion, a flaw shared by the other members of the Tribunal, with the possible exception of Hisomi. She callously disregards Chu-Hsi's death which was largely the Ninja Tribunal's fault due to their refusal to ally with him. Her belief in the greater good results in a cold and almost cruel disregard for the lives around her.
 * Hisomi-Shisho: The Ninja Master of Stealth, who no longer speaks; He seems to be the most compassionate member of the Ninja Tribunal and unlike the others, who show a callous disregard for the lives of others, he never shows any indication that he would sacrifice his acolytes for the greater good. He is the only member of the Ninja Tribunal who doesn't degrade, insult or even ignore his students.
 * Nano/The Recycle Kid (Lara Jill Miller): A collection of nanobots who created a body for themselves out of discarded junk; due to having little experience with the world, he has a childish outlook, which makes it easy for a group of streetwise punks to take advantage of him. Thanks to the efforts of the Turtles and their new ally, Junkman, Nano was guided onto the path of righteousness and became Junkman's partner, The Recycle Kid.
 * The Junkman/Arthur Mason (Rodger Bumpass): A self-proclaimed "superhero of the junkyard" who acts as the leader of the homeless people, convincing them that just because things are old doesn't mean that they're useless. He once took a teenage boy as his apprentice, but the boy corrupted his teachings and became the obese "Garbageman". He considers Nano to be like the son he never had, and was willing to help guide him on the path of righteousness.
 * Stump and Sling (Billy West [Stump] & Wayne Brady [Sling]): A pair of Birchians (aliens that resemble trees) whom are the co-proprietors of the Stump Intergalactic Wrestling Federation, a wrestling circuit located on a Pluto-sized asteroid christened "The Stump Asteroid". They are easily-manipulated when it comes to money, which we see when it's revealed that they made a deal with the vile Queen Maligna.
 * Zed Lakin, Razz Charkov, & Kree Skalpach (Mike Judge [Zed & Razz], & Tracey Grandstaff [Kree]): Three benevolent Triceratons who work as announcers covering the wrestling matches at the Stump Arena. They later help the Turtles and their friends make their getaway, due to all of them being seriously pissed at Stump and Sling for selling out due to greed.
 * Cherubae/Mary Bones (Estelle Swaray): An enigmatic, dimension-hopping sorceress who is the warden of Dimension X's prison zone, and the lover of Cudley the Cow-Lick (the less said about how that works, the better). She was the one who used her powers to strip Krang of his body and aided Mortu in banishing him to Earth, as well as aiding in the creation of the Muta-Stones and the Turnstone, a spherical, translucent orb that allows people to conjure things with only their thoughts. When she is on Earth, she assumes the identity of Mary Bones, a mysterious old woman who lives in the same neighborhood as April and Zach, though the kids refer to her as "Creepy Ol' Rattling Bones".
 * Detective Kara Lewis (Nicole Sullivan): A police officer who tried to investigate the cases about the Foot Clan and the mutants and found herself in over her head until the Turtles saved her. Grateful, she used her position to help cover up for them, and worked with them, the 'Jim Gordon' to their 'Batman', only younger and hotter (in Raph's words). Shortly after, since she had the most experience dealing with the Turtles and their antics, she was made Head Commissioner of the New York Police Force.
 * Metalhead Classic (Greg Berger): A robotic Turtle built by Donatello and Irma; upon activation, he identified Don as "father" and Irma as "mother", though they had to use him to duel with Viral within the Cyber-World. He is able to incorporate any fighting style into his database and replicate it, as well as his head being the mind of a gigantic Turtle Mech for the giant monster battles. He's equipped with a highly-advanced AI microchip, which allowed him to develop sentience and emotions (as well as upgrading himself when needed) that came in handy when he managed to reason with the rampaging, childlike Nano, whom he calls 'brother'.
 * Timothy Jackson/The Pulverizer/The Mutagen Man (Justin Berfield): A friend of Zach's who learned of the Turtles' existence following their battle with Krang's assassins; afterwards, he made himself a costume (resembling the 2003 Turtles) and dubbed himself "The Pulverizer", attempting to start a career as a vigilante. However, he quickly learned that typical street fighting knowledge wouldn't be enough to take on villains, so he planned to infiltrate the Foot Clan in order to act as an informant for the Turtles. However, as part of the "initiation" ceremony, he was doused with mutagen that turned him into a formless mass of innards. Relying on a containment suit to keep himself together, he was called "The Mutagen Man", and used as the Foot Soldiers' heavy hitter, until he was captured by Null Corp, and she promised him a retromutagen if he obeyed her orders.
 * Professor Honeycutt/The Fugitoid (Tom Kane): A scientist from a future where the Triceratons have ravaged Earth, being mortally wounded during the process and transferring his brain to his robotic unit S.A.L. to keep himself alive. Becoming part of a group called "The Timekeepers' Society" to prevent the dark future from happening, he doesn’t always agree with the Time Council’s methods and has bent the rules several times, especially when to help his new friends, the Ninja Turtles. Enigmatic and eccentric, yet behind his jovial and outgoing facade lies a brilliant and calculated mind. However, trying to stabilize the time stream often takes harsh decisions on his own part, but he often tries to minimize the risk whenever he can. Though he's very knowledgeable about the nature of time, he says it still has ways of befuddling him, as time is unpredictable.
 * Renet 'Caitlin' Tilley (Bex Taylor-Klaus): Professor Honeycutt’s 13-year-old female apprentice among the timekeepers; excitable and mischievous, she admires the professor and sticks up for him when the Time Council berates him. She has a habit of getting herself into trouble but often makes up for her mistakes in the end. Since the Professor's robotic body can’t use a Time Scepter, Renet has to work it for him, though she is still inexperienced with it. Despite this, she shows promise as a great timekeeper, & has a crush on Zach, who feels the same way. She lives in the present day under the alias "Caitlin Tilley", a student at Robert F. Wagner Middle School.
 * Michael Sandelheim/Lord Simultaneous (Bob Joles): Head of the Time Council, superior of the Fugitoid and Renet, and is often annoyed that they ‘bend the rules’ to get what is done. He is gruff but has the best interest of the time-stream in mind and has respect for Professor Honeycutt and Renet. The two may give him a headache at times but despite his cranky demeanor is actually very fair and kind.
 * Ninja-Saurus Wrecks: A quintet of mutated dinosaurs who were saved from extinction by the Turtles, and were later taken to the future by the Turbo-MNT in order to be properly trained. They're an homage to The Land Before Time series, as well as We're Back! A Dinosaur's Story.
 * Ajax (Zach Callison): A mutant Apatosaurus who was mutated during Savanti's time battle with the Turtles, he is curious and bold.
 * Zura (Anndi McAfee): A female mutant Triceratops who was brought onto the team by Shadow. She is big on heart and on physical prowess, but would rather punch and ask questions later. She doesn’t use weapons, instead preferring to use her bare hands for combat. She is very laid-back and lighthearted but likes a good fight and is eager to get to work.
 * Lope (Justin Roiland): A snippy, wisecracking mutant Saurolophus who was also mutated during Savanti's time-battle.
 * Wingding (Malique Richardson, imitating Jeff Bennett & Will Ryan): A mutant Pterodactyl who was also mutated during Savanti's time-battle with the Turtles.
 * Stego (Kyle Hebert): A seemingly-slow, yet secretly deep-thinking mutant Stegosaurus.
 * Tarbo (E.G. Daily): A headstrong mutant Tyrannosaurus Rex.
 * Lothar (Tony Daniels): A curious yet jovial caveman who ended up getting taken to the future along with the dinosaurs; the mutagen granted him intelligence.
 * Turbo Mecha Ninja Turtles: A sextet of trained ninjas in robotic Turtle mech suits, each of them color-coordinated to the past TMNT. While Michelangelo, Jr. is the only member of the team to be Mikey and April's biological child, the other four are adopted orphans...and the 5th is Casey and Gabrielle's son. Like the original Turtle Titan before them, they have a very Super Sentai/Power Rangers/Kamen Rider-vibe, due to wearing Kamen Rider-style outfits outside of their mechs, and they do Super Sentai/Power Rangers-style poses before battle (referencing " Megabot: The Cosmic Defender ", which Leo is ecstatic about).
 * Michelangelo Buonaroti "Mikey" Splinterson-O'Neil, Jr./Turtle Titan II (Kyle Massey): Michelangelo and April's first-born son and the de facto leader of the Mecha Turtles. He pilots a sky-blue (later changed to silver) Turtle mecha, representing his aunt Venus.
 * Basil "Basque" Splinterson-O'Neil (Kevin Michael Richardson): Mikey Jr's older (adopted) brother, and the soft-spoken tech genius of the Mecha Turtles. He pilots a purple Turtle mecha, representing his uncle Don.
 * Frieda Splinterson-O'Neil (Kari Wahlgren): Mikey Jr.'s older (adopted) sister, and the loose-cannon brat of the Mecha Turtles. She pilots a red Turtle mecha, representing her uncle Raph.
 * Kusama Splinterson-O'Neil (Genevieve Knight "G." Hannelius): Mikey Jr.'s younger (adopted) sister, and the hyperactive ray of sunshine of the Mecha Turtles. She pilots an orange Turtle mecha, representing her adopted dad...and Mikey Sr. couldn't be prouder.
 * Jackson Splinterson-O'Neil (Ramone Hamilton): Mikey Jr.'s younger (adopted) brother, and the stoic, ronin-type of the Mecha Turtles. He pilots a navy-blue Turtle mecha, representing his uncle Leonardo and aunt Karai. He's a little jealous that Mikey Jr. gets to be the leader. though.
 * Cody Hamilton Johansson-Jones (Jay Gragani): The son of Arnold "Casey" Jones, Jr. and Gabrielle Johansen, he's the "wild-man" of the Mecha Turtles. He pilots a jet-black Turtle Mecha, representing his uncle Slash.


 * Robyn O'Neil (Novie Edwards): April and Zach's older sister, currently in college. She first appeared in mid-Season 2, living at the old farmhouse up in Northampton, and warned Mike that if her little sister ever got hurt, he would have to deal with her.
 * Weazel (David DeLuise): A space pirate from Dimension X who is recruited by the Neutrinos & the Turtles to help them beat General Traag.
 * Mortu (David Fielding): The benevolent leader of the Utroms, masquerading as the new head of the TGRI company by the end of Season 1. After he and the turtles become allies, he provides them with a new home and resources, and later helped to find an underground city where mutants and aliens could live in peace without being pestered by humankind. Though his people were eventually able to return home, he still came to the Turtles’ aid many times, and in return the Turtles helped Mortu out of trouble.
 * Xeinos (Tress MacNeille): A female Utrom who is Mortu’s secretary and bodyguard, and the one who was responsible for raising Leatherhead, being called ‘Momma’ by him. She was the inventor of the exo-suits that allowed the Utroms to mingle with humankind.
 * Regina Campbell/Queen (Yvette Nicole Brown): One of the leaders of the EPF, a powerfully built African-American woman. She is not as obsessive as Bishop but nonetheless has her share of questionable and harsh methods. Unlike Bishop, she has a more positive interest in the Turtles and was willing to work with them on occasion.
 * Agent Ravenwood (Michelle Knotz): A longtime agent of the EPF, Ravenwood was the subject of a failed experiment many years ago that left her with unusual physical qualities. This includes a body that can stretch, endure physical assaults from fierce, strong mutants, and split into multiple different "Ravenwoods." She takes a more pragmatic attitude than Agent Bishop, and though she wants to stop mutants who make themselves dangerous to others, she also believes that they deserve compassion, viewing humans as responsible for a mutants' anguish and personally relating to that anguish.
 * Shadow Splinterson-O'Neil (Cricket Leigh): Daughter of Michelangelo and April O’Neil in the future. She has her mother’s ninjutsu skills and brilliant mind, but her father’s aptitude for mischief. She is the leader of the Neo-TMNT, a splinter group to the Turbo-MNT. She is struggling with the legacy of her parents and has a lot to live up to, causing her to push herself as a leader and a warrior. Despite being anxious, she is a natural-born leader. She is skilled with a variety of weapons, from blades to fans to spears. Though like her uncle Casey, she at times uses sports gear like hockey sticks and baseball bats, and she is able to switch weapons on the fly easily. She thinks her younger brother's "superhero club" is ridiculous, although she envies him sometimes.
 * Metalhead-X (Greg Berger): Metalhead's upgraded form from the future. Though he can download any program to learn ninjutsu quickly, he intends to learn them all naturally, like any organic. He desires to become "a real boy" one day, though he does not always fully understand them. His preferred weapon is a laser lance, though he has various other gadgets and weapons.
 * Dirk Savage (Jack Black): Originally a mutant hunter and partner of Simon Bonesteel, Dirk soon found himself in danger of being eaten by a Squirrelomorph, but he was rescued by Pigeon Pete, which made him realize that not all mutants were bad. Since then, he's become a pro-mutant supporter, and currently lives in the newly-liberated Mutantropolis.
 * Miyamoto Usagi/Rabbit Ronin (Eric J. Vale): An anthropomorphic rabbit samurai who accidentally got transported to the Turtles’ world after a failed dimensional portal experiment by Ch’rell. Being wary of ninja due to them having a bad reputation in his world, he first battled the turtles, but befriended them soon afterwards. He has crossed over several times to the Turtles’ world and vice-versa. As a born samurai, he is loyal and very honorable, as well as being very brave and having a great sense of justice.
 * Murakami Gennosuke (Alex Hirsch): A rhino samurai who is Usagi’s friend. He had his horn chopped off by an evil warrior long ago. He is lazy, laid-back, slightly greedy and opportunistic, not to mention having a rep as a con artist, but deep down he’s a good guy. While a bit cowardly and not actively seeking battle, he cares for Usagi’s well-being and has overcome his fears several times to help him, and is shown to be a great warrior in his own right.
 * Otome Ame (Ashleigh Ball): A female anthropomorphic cat who is Usagi’s close friend. She is the bodyguard of Lord Noriyuki, a job she is utterly devoted to. While serious when the situation asks, she gets real cheeky and flirty with Usagi, who is initially flustered by her attempts.

Villains

 * General  Commander Krang/Dr. Patrick G. Coleman (Jess Harnell [as Krang], Roger L. Jackson [as Dr. Coleman]): An exiled Utrom warrior/tactician/scientist/criminal mastermind/arms dealer from a place called "Dimension X"; 3 years before his exile to Earth, he met and courted the Balaraphonian empress Shreeka, with whom he had a son, named Ch'rell. However, he wouldn't get to see Ch'rell grow up, because due to his many, MANY war crimes, he was stripped of his body [see the 1987 episode  "Invasion of the Krangazoids"  for an idea of what Krang's body looks like] by the Neutrino leaders and exiled to Earth by Cherubae, where he was left as a disembodied, brain-like being with two little tendrils for arms. Shortly, he was found and taken in by the 6-year-old prodigy Jake Chaplin, whom he promised to share scientific knowledge with if he could aid him in constructing a transport device. Using the scrap-metal that Jake collected from the Long Island Junkyard, Krang managed to construct an assortment of unusual weapons, as well as 2 android bodies: one to disguise himself to the public, and one for combat purposes, which he used to convince the Purple Dragons street gang to join up with him. 16 years before the Turtles first came to the surface, he took on the identity of "Dr. Patrick Garrett Coleman" [a reference to his 2 voice actors from the 1987 cartoon and the one in the 2016 Out of the Shadows film], and became the CEO of the TGRI [Techno-Global Research Institute] corporation, which is secretly a front for him to construct his ultimate weapon of destruction—the Technodrome.
 * Ch'rell/Carlos M. Coleman (Brian Drummond [as Ch'rell], Bumper Robinson [as Carlos]): Krang and Shreeka's son, who is 89% Utrom, 11% Balaraphonian. On the day of his 13th birthday, he learned of his father's fate, and refusing to believe that he had perished, ventured to Earth solo in order to mount a rescue mission for his father. However, when he arrived he learned that his father had carved out a living for himself, and managed to create the purple Mutagen that would soon contribute to the mutation of the Turtles, Splinter, and Whisker. He also owns his own pair of android bodies, due to the fact he greatly admires his father. But that doesn't mean he won't try to strike out on his own and launch some of his own plans...
 * Krang's Assassins - A five-person gang of the most fearsome mercenaries in Dimension X, all of them under the service of Krang.
 * K'Vathrak the Newtralizer (Jack Angel/Dale D. Kelly): A cyborg salamander armed to the teeth with an assortment of weapons.
 * Scumbug (Mark Oliver): A mutant roach-man and a former exterminator, toting a tankful of poisonous gas on his back.
 * Tora (Alexander Polinsky): A Traglodoonian assassin/bounty-hunter who is Shogun's partner, and fights using his cryokinetic (ice) powers, which he derives from a Dimension X weather machine.
 * Shogun (Maurice La Marche): A cycloptic robot bounty hunter who comes from Sector Six of the Dead Star Zone in Dimension X. He fights armed with a naginata, as well as his removable head; he also has the ability to alter his voice to sound like anyone he wants to fool his opponents.
 * Antrax (Danny Cooksey): A human-sized alien ant from Dimension X, and Krang's chief executioner; clad in an executioner's hood, he wields a pair of battleaxes in order to chop his foes to bloody chunks.
 * Empress Shreeka (Grey Griffin): A Balaraphonian empress, Krang's mate, and Ch'rell's mother. She first encountered Krang on the field of combat, and they developed a mutual respect for one another which soon became a romance, built on terrorizing the galaxy and subjugating alien races.
 * Mung the Kabutomushi (David Prowse): Krang's hunchbacked informant and subordinate who is a member of the beetle-esque alien race known as the Kabutomushi. Despite his feeble appearance, Mung is known for his devious intelligence and skill in technology and engineering, not to mention his powerful mental abilities (a reference to David Prowse's physical-only role as Darth Vader).
 * General Traag (Jason Isaacs): The undyingly-loyal leader of Krang's rock soldiers; he possesses the ability to spew molten lava from his mouth at opponents.
 * Lieutenant Granitor (Jon Kassir): Traag's second-in-command, who speaks in a voice similar to the Crash Bandicoot villain N.Gin. He's a bit clumsy, and somewhat forgetful.
 * Drakus/Sgt. Berzerko (James Arnold Taylor): Krang's weapons engineer and the one who helped design the blueprints for the Technodrome. When in mobile combat, he utilizes a super-tank called The Annihilator, which despite being smaller than the Technodrome, is 20 times as powerful.
 * H.A.V.O.C.: Highly-Advanced Variety of Creatures: A pro-mutant organization similar to the Brotherhood of Mutant Terrorists from X-Men that started in the future, but its leader traveled back in time to ensure the group began much earlier.
 * Titanus/Darius Dunn (Jeffrey Tambor): A smug, rotund, green-skinned, red-eyed mutant of unknown origin with a good-natured facade, as well as the founder of the underground city, Mutantropolis. In actuality, however, he has an elitist personality similar to the X-Men character Magneto, believing that mutants are the superior beings & that humans exist solely to serve them. He is secretly the founder of the pro-mutant/anti-human organization H.A.V.O.C. (Highly Advanced Variety Of Creatures); in public, he masquerades as the human businessman Darius Dunn, a facade that has gone unnoticed by everyone except the Turtles and their allies.
 * Big Mama (Lena Headey): A Jorōgumo who can change between her human form and her humanoid spider form. She is the owner of an extra-dimensional gladiator arena called the Battle Nexus which is hidden in the secret sub-level of a hotel that is owned by her human form (and financed by Darius Dunn, so his mutant acolytes have room and board, as well as a place to hide from humanity). Big Mama uses the Oozesquitos in her possession to mutate anyone into mutants so that they can fight for her entertainment in the Battle Nexus; she is apparently in a relationship with Old Hob.
 * Old Hob (Steve Blum): A surly, eyepatch-wearing mutant cat, Ringtone's adoptive brother, Big Mama's lover, and Titanus' right-hand enforcer in Mutantropolis, as well as in H.A.V.O.C.
 * Ringtone (Judd Nelson): A mutant raccoon who is an agent of H.A.V.O.C., and Hob's adopted brother; he has enhanced night-vision, agility, and can launch supersonic boom-blasts to stun his foes.
 * The Circus Creeps: A team of mutant animals who were once circus performers, but now aspire to turn humanity into their servants, and as a result, gain support from Titanus' civilian alter-ego, Darius Dunn.
 * Kodiak the Great (Richard Doyle): Formerly a ringmaster for the Kamonte Brothers' Circus, he was mutated into a humanoid Kodiak bear, who prefers to fight using his whip.
 * Serpentina (Kathleen Barr): Formerly a dancer for the Kamonte Bros' Circus, she was mutated into a humanoid snake-woman, who prefers to hypnotize her opponents and then constrict them with her coils.
 * Hypno-Potamus (Alfred Molina): He was originally a magician/hypnotist who worked for the Kamonte Bros' Circus (usually paired with Serpentina), but he and his pet hippopotamus, Andy, were fused together into a humanoid hippopotamus-man, who uses various classic magic tricks to battle and subdue his foes.
 * Sawtooth (Richard Horvitz): A hot-blooded Canadian lumberjack who was transformed into a mutant beaver with long sharp fingernails, razor-sharp teeth that can break through a tree in three bites, and a bionic tail with built-in razors and buzzsaws to hack his foes to pieces.
 * Saeko Coleman/The Shinigami (Tania Gunadi [Season 1], Jennifer Hale [Season 2] & Kari Wahlgren [Season 3]): An orphan from Japan who was taken in by Krang, whom despite his crude tendencies and grumpy attitude, raised her and Chaplin as though they were his own children. He also trained her in several forms of martial arts, which she uses to keep the Purple Dragons in line. She chose the nickname "Shinigami" [translating to "Death God"] due to possessing an innate love [bordering on lust] for destruction. She is quite playful when it comes to battle, often treating it like a game, and can be quite creepy. She has a crush on Michelangelo, but Mike is very, VERY creeped-out by her. The fact that she likes to lick his face in an...odd manner doesn't help either.
 * El Puno del Tigre/Tiger Fist (Eric Bauza): A mutant tiger who moonlights as a luchador in the Underground Wrestling Federation, and Raphael's favorite wrestler.
 * Charlene 'Charlie' Desmond/Killerwatt (Kristen Chenowith): An adrenaline junkie who was chosen as one of the test subjects for Dr. Coleman's experiments, which granted her the ability to absorb and shoot electricity. Since she entered the U.W.F., she has fallen head-over-heels in love with Raphael, but she is obsessed with him and will harm anyone who tries to take him from her.
 * Vid Vicious (Rob Tinkler): A technophobe hermit who is merged with the parts of a satellite and transformed into a cyber-mutant who uses the TV on his chest (which cannot be shut off unless someone breaks it) to suck people into the TV universe. Wonder if he's got HBO...?
 * Agent John Bishop (Steven Jay Blum): One of the leaders of the EPF (Earth Protection Force), he is completely paranoid when it comes to mutants and aliens, believing them all to be a threat after an accident in Roswell has killed his father. He is determined to wipe them all out, and has done many immoral things to do so, all while claiming he does it for the good of the country.
 * Garson Grunge/The Garbageman (Jim Cummings): Junkman's former apprentice-turned-arch-foe; originally, he was an orphan taken in by Junkman, but he "twisted and corrupted the powers of garbage", wanting to use it to conquer instead of recycle and protect; as a result, he abandoned Junkman and spent the next 12 years of his life building up his empire of filth and villainy.
 * Oroku Saki/The Shredder (Maurice LaMarche): The leader of the Foot Clan, Oroku Saki, was originally a Foot Clan member, and the best friend of Hamato Yoshi. He had an older brother, Oroku Nagi, who was arrogant, power-hungry and vain. Nagi and Yoshi both loved Tang Shen, but Nagi attacked Yoshi out of jealousy. After being banned for his dishonorable ways from the Foot Clan, he started a rebellion and plans to overthrow the head of the Foot. Yoshi set out to deal with Nagi, Saki begging his friend not to kill his brother. Yoshi made a promise, but wasn’t able to keep it as he was forced to kill Nagi. Saki felt betrayed and broke his friendship with Yoshi, and became his enemy. He took over the splinter group his brother Nagi had created and eventually enveloped the rest of the Foot Clan. Yoshi fled with Tang Shen in shame as he couldn’t bring himself to fight Saki and defend the Foot properly, though Splinter did not tell the Turtles out of fear they would think less of him. Motivated solely by revenge, his only goal is to wipe out the Hamato bloodline which caused him grief. However, he has a sense of honor, even if it is somewhat twisted and won’t sink to certain lows, and in the face of an opponent more dangerous, he is forced to team up with the Turtles and developed something of a respect for them. Despite his anger at Hamato Yoshi, he genuinely does wish to be friends with him again, and even though he's an intimidating villain, he does have a few goofy moments like his 1987 counterpart, whom he actually respects and wants to help in regaining his former threat level.
 * Dragon Lord (Corey Burton): Formerly the 5th member of the Ninja Tribunal,
 * Oroku Karai/Lotus Blossom (Olivia Olson/Emily Bauer-Jenness): Shredder’s young, rebellious teenage daughter who likes doing things her own way. She cares about her father, but can get annoyed with his overbearing nature. She doesn’t hate the turtles and is even somewhat friendly towards them in her spare time but when she is on the job she is willing to fight them. She has a sense of honor that is less twisted then her father’s, and she has a positive interest in Leonardo, even having a crush on him. However, as she loves her father, she assists him in any wicked schemes he is up to, and is forced to fight the Turtles as a result.  As the natural daughter of the Shredder, she was the result of Oroku Saki finding love again with a different woman and considered stepping down from leading the Foot to raise a family, though shortly after Karai’s birth, her mother was killed by what was believed to be a rival crime syndicate, though there are suspicions that someone in the Foot had done it so that Shredder wouldn’t stray from his current path.
 * Hattori Tatsu (Michael Dobson): An Elder Foot clan retainer and personal assistant of the Shredder. He is completely loyal to the Shredder, but felt that his wife was holding him back from fulfilling his potential and had her murdered.
 * Norinaga (Eric Bauza): A member of the Foot Clan who's named after the 15th-century daimyō, and has a mild rivalry with Tatsu. He subsequently takes his place after Shredder kills Tatsu.
 * Beanpole (Don Brown): A thin, lanky Foot Lieutenant who prefers to use stealth and strategy when fighting. He talks in a scratchy voice.
 * Colossus (Maurice LaMarche): A large, bulky Foot Brute and the muscle of the duo, who naturally uses force and fists when fighting. He has a tendency to sometimes treat Karai like a young child, though it's mostly because he cares about her safety. He talks in a deep, bulky voice.
 * Razorbeak (Charlie Adler): A ruthless, sycophantic mutant peregrine falcon who is Beanpole's pet (he "wanted something that could claw out [his] enemies' eyes"), and the main messenger of the Foot Clan—Karai calls him "Dad's ninja stool pigeon", though it's mostly because whenever Karai or Shinigami sneak out, Tatsu makes Beanpole dispatch him to keep an eye on them & monitor their locations.
 * Hachiko/Dog-Pound (Andrew "Andy" Kishono): Formerly Saki’s pet dog Hachiko, he turned into the humanoid dog monster Dog-Pound after being exposed to mutagen. His canine loyalty has carried over to his mutant form, and with his newfound ability to think coherently, speak and fight he is able to protect his master like he never could before. Loyal to the end, he is not only a pet, but Shredder’s most valuable lieutenant. As Dog-pound, Hachiko has greatly enhanced strength and endurance and his arms are covered in bony plates and spikes which can block attacks and can pierce through even steel. As a dog he also has a good sense of smell and hearing. Though he still has some animal instincts, as things like hydrants, squeaky toys and being scratched on the ear can still distract him.
 * The Purple Dragons: A notorious street gang who regularly make trouble in the city of Manhattan; as of Season 2, they work under the Foot Clan.
 * Hunter "Hun" Rocksteed (David Kaye [Season 1], Patrick Pinney [Season 2]): The six-foot tall leader of the gang, and Rocksteady's older brother; he usually follows Shredder's orders to a T, but spends his spare time playing video-games on his laptop.
 * Kendra (Tania Gunadi): A snobby, snarky tech specialist (and Hun's girlfriend) who prefers to identify with the PDs by wearing a jacket with their emblem on it instead of the arm tattoo (she's not a big fan of needles). She's the lead hacker of the gang who is a wiz at reprogramming technology to pull off complicated heists.
 * Jeice (Jimmy Zoppi): Kendra's helper and the demolition expert.
 * Anton "Bebop" Ziktor and Owen "Rocksteady" Rocksteed (John DiMaggio [Bebop], Jeff Glenn Bennett [Rocksteady]): Two physically powerful but not-too-bright Purple Dragon members and lifelong best friends who were forcibly drafted to be part of the Shredder and Hun’s experiments to create mutant followers; previously Rocksteady was a masked wrestler and Bebop was his manager. With Bebop becoming a mutant warthog and Rocksteady a mutant rhino, their physical prowess makes them difficult enemies for the Turtles, though what they have in brawn is not balanced out with brainpower. They only joined the Foot because they wanted to do something great with their lives and prove that they weren't useless idiots—though their destiny is much greater than either of them are aware.
 * Sala-Raptor (Rebecca Shoichet): A mutated salamander with 50% raptor DNA.
 * Fish-Face (Justin Shenkarow): A piranha from Shredder's private collection of tropical fish who was transformed into a monstrous mutant after being exposed to mutagen. Afterwards he was given a special breathing apparatus and mechanical legs so he could function on land as well as in the water. He's loyal to Shredder, but bloodthirsty and cruel, prone to antagonizing his allies and needs to be watched regularly to keep him in line. He has gained something of a rivalry with Raphael, as well as with Dog-Pound, as he is jealous that a ‘street mutt’ has become equal in rank as him. Shredder sometimes has to literally keep him on a leash (even moreso than Dog-Pound) due to his aggressive and bloodthirsty nature.
 * Sharktooth (Adam Wylie): A mutant tiger shark and Fish-Face's self-proclaimed "little brother"; he also wears a breathing apparatus and mechanical legs so he could be like Fish-Face, much to his annoyance.
 * Spikeback (Ian James Corlett): A mutant pangolin that can curl into a ball, as well as roll over and bounce on his opponents.
 * Walker (Daran Norris): A notorious criminal in New York who smuggles weapons and is an arms dealer for the Purple Dragons. Walker is skilled not only with firearms, but also a bit in martial arts.
 * Chef Sculpin (Alan Rachins): A mutant lobster who works as the Foot Clan's co-head chef.
 * Rupert Gourmand/Chef Porkbelly (Zachary Bennett) A mutant pig who is Sculpin's mentor, and Bebop and Rocksteady's adoptive father; he usually creates mutant food-creature hybrids to serve the Foot...though his soup du jour is exquisite. He used to be a celebrity chef with bizarre eating habits, cooking many strange dishes in his restaurant as well as having his own show: The Gourmet Gauntlet. One day his life changed while he was preparing a pork dish, he was doused with mutagen, turning him into a massive bulky hog with punches that hit with the force of a Mack truck, shooting flames and laser loogies from his acid-filled stomach and he wields a giant fork and knife as his weapons.
 * The Hell-Shells: A quintet of evil Ninja Turtle duplicates created by Dr. Quease; however, when the scientist planned to use them for painful experiments, they quickly revolted and escaped. Now they work for themselves, sometimes joining forces with the Turtles to take on greater threats, but most times they'll try to terrorize, humiliate, or torment them.
 * Lethalnardo (Seth Green): Leonardo's evil duplicate, & the leader of the Hell-Shells; he is charismatic and charming, but very dangerous. He has a sadistic streak but mostly lets others do most of the work unless something or someone draws his personal attention. He fights dirty and thinks of his siblings as expendable, but fakes being a good brother and leader. He is completely amoral and only cares about his own twisted sense of fun.
 * Doomatello (Josh Brenner): Donatello's evil duplicate, & the mad scientist of the Hell-Shells; unlike Donnie, he is cold, barely emotive, lacks empathy & is arrogant and nihilistic. Like Donnie, he's a genius when it comes to concocting chemical brews to use as explosives or to inflict harm.
 * Ravagael (Matt Stone): Raphael's evil duplicate, & the most violent member of the Hell-Shells, with a temper to match, beating people to a pulp at the slightest provocation. He often butts heads with Lethalnardo about his leadership but is forced to fall in line each time as he is no match for him.
 * Manicangelo (Trey Parker): Michelangelo's evil duplicate, the most unhinged member of the Hell-Shells, & an unpredictable wildcard who is hard to control, even for Lethalnardo; he often makes cruel jokes at the expense of others and can be seen laughing maniacally.
 * Venomous De Milo (Cree Summer): Venus' evil duplicate, & the most battle-hungry member of the Hell-Shells; she loves nothing more than to fight, and cares only for battling worthy foes. She has no mercy for the weak, and believes that those who can’t keep up are left behind.


 * Lord Dregg (Simon Templeman): A bug-like alien who is one of the first children of Queen Maligna, Dregg is a shifty, snide, corrupt businessman-type fellow who commands a team of soldiers called the TeknoGang to enforce his rule upon the universe.
 * Hi-Tek (Brian Austin Green): Leader of the TeknoGang, and Dregg's lead associate.
 * Victor Falco/The Rat King (Charlie Adler in his debut, Corey Burton in all other episodes, Brian Drummond in his final appearance): Originally a scientist who had a particular fascination with rodents, Falco despised Baxter Stockman when he invented his M.O.U.S.E.R. robots to help reduce the city's rodent population; so when he attempted to sabotage the machinery, Baxter caught him in the act, and Falco retreated from society, hiding out in the sewers and clad in tattered clothing. During his time alone, he trained his mind to develop psychic powers to communicate with and control the rats scurrying around, disguising his power with a makeshift flute, as an allusion to the Pied Piper. He soon resurfaced, attempting to kill Stockman in revenge, but was beaten by the Ninja Turtles. He would return to menace them a few more times.

Trivia

 * Originally, Scott D. Menville was selected to voice Raphael, but Flynn changed his mind when he heard Curtis Armstrong's performances in Dan Vs. (as the title character) and as Schmuely "Snot" Lonstein from American Dad!. Looking back, he feels like he made a good choice.
 * Menville sometimes fills in for Armstrong when he's not available, though, like in the Shell-Shocked videogame.


 * Also, Kyla Pratt was originally chosen to voice Venus, but was replaced by Cathy Cavadini, due to scheduling conflicts for Pratt. Ironically, fellow Powerpuff Girls alumni E.G. Daily provides the voice of April from Season 3 onward.
 * Oroku Saki was originally meant to be voiced by Peter Cullen, but was recast with Ryo Horikawa after Fletcher saw his voice work as Vegeta in Dragon Ball Z, as well as Horikawa displaying his bilingualism, being able to speak both Japanese AND fluent English.
 * Lethalnardo is voiced by Seth Green, who played Leo for the final 3 seasons of the 2012 CGI cartoon, as well as on Green's 11-minutes-per-episode stop-motion comedy series Robot Chicken.
 * Doomatello is voiced by Josh Brenner, who voices Donatello in Rise of the Teenage Mutant Ninja Turtles; subsequently, he inherits some of 2018 Donnie's "mad scientist" traits, except cranked up to 11.
 * Kyle Massey & Jaleel White were cast as Michelangelo three months before Brandon Mychal-Smith was cast as 2018 Mikey, thus chronologically making them the first African-American voice actors to portray a Ninja Turtle, followed by Phil LaMarr as Donnie.
 * Trevor DeVall was originally chosen to voice Sgt. Bananas, but Flynn recast him with Mike Judge, due to watching scenes of his voice-only role as Coach Buzzcut from Beavis & Butt-Head.
 * This is the second series to make Baxter Stockman a Caucasian, as well as a sympathetic (if not pitiable) figure instead of a deranged, selfish megalomaniac.
 * The choice to make Baxter Stockman an ally instead of an enemy was inspired by a rejected idea that was proposed during the production of the 1987 cartoon's 3rd episode, "A Thing About Rats". Flynn also chose to go through with it because he felt that regardless of the incarnation, Baxter always got the short end of the stick.
 * Casey's older sister Tiffany Jones is based on (in personality and voice) the character Sally Avril from The Spectacular Spider-Man, who was also voiced by Grey DeLisle-Griffin.
 * This is the first incarnation of the series to give the Turtles middle names, and the second to refer to them by the last name "Splinterson" (which originated in the 2003 4Kids series).
 * This is the first incarnation of the franchise in which Tang Shen doesn't die, and the third in which she is somehow involved in the conflict between Yoshi and Nagi.
 * Chef Porkbelly is this universe's counterpart of Meat Sweats (from Rise of the Teenage Mutant Ninja Turtles).
 * As of January, Flynn has chosen to do adaptations of the classic TMNT film trilogy taking place in the Hard-Shell universe—or at least, a universe that's nearly identical to it, albeit with some timeline changes.
 * W. Morgan Sheppard was originally cast as Lord Dregg, but following his death, Simon Templeman has replaced him.