Teenage Mutant Ninja Turtles: The Fifth Mutation

 is an American action-adventure cartoon being both a reboot and sequel to the Teenage Mutant Ninja Turtles franchise airing on Nickelodeon since June 15th, 2022.

Synopsis
After the defeat and arrest of the Shredder, the Turtles believe that they know all of their threats when suddenly they discover a fifth turtle, a rebellious turtle known as Jennika as they have to band together to face against new and returning threats.

Main

 * Leonardo "Leo" (voiced by TBD) - the determined and slightly stressed leader of the Turtles who has gotten used to protecting New York as he soon tries to get used to learning there is a fifth mutation.
 * Raphael "Raph" (voiced by TBD) - an anger prone mutant turtle who can sometimes get too violent sometimes as he surprisingly starts to bond the most with Jennika.
 * Donatello "Donnie" (voiced by TBD) - a nerdy mutant turtle who enjoys building inventions to help the Turtles as he slightly sucks at interacting with the other turtles.
 * Michelangelo "Mikey" (voiced by TBD) - a goofy and lighthearted mutant turtle who is happy that he has a sister although he can sometimes annoy his siblings.
 * Jennika "Jen" (voiced by TBD) - a rebellious mutant turtle who was being hunted down by the paramilitary organization known as Dark Water, slowly starting to bond with her brothers as well.

Supporting

 * Splinter (voiced by TBD) - an aging mutant rat who was the pet rat of the deceased Hamato Yoshi as he trained the Turtles in multiple martial arts, being willing to train Jennika as well.
 * April O'Neil (voiced by TBD) - a scientist who has recently taken over TCRI from Baxter Stockman, being a close friend and ally to the Turtles, often helping them out.
 * Casey O'Neil (voiced by TBD) - a cocky vigilante who has married April as he keeps his job as a vigilante, often working with Turtles as well as starting to grow interested in Jennika.
 * Oroku Karai (voiced by TBD) - Shredder's daughter who helped the Turtles overthrow him as she has reformed the Foot Clan to become a secretive group of protectors, making the Turtles honorary members and occasionally asking the Turtles for help.

Antagonists

 * Dark Water - a mysterious and sinister military organization who has been studying the mutations over New York, wanting to build their own mutant weapons, clashing against the Turtles.
 * Director Wesley Knight (voiced by TBD) - the calm and sinister yet occasionally mad leader of the Dark Water who was responsible for creating Jennika as he wants to get her back no matter what, claiming her to be his "daughter."
 * Alexandra "Alex" Winters/Megavolt (voiced by TBD) - a cocky operative of the Dark Water who wears a high-tech suit that allows her to control electricity itself, being loyal to Director Knight.
 * Dirk Savage (voiced by TBD) - an anger-prone operative of Dark Water who was mechanically advanced to help fight for Dark Water, being sent to hunt after and capture mutants.
 * The Rat King (voiced by TBD) - a flamboyant yet mysterious god-like entity who claims to have existed since the dawn of time itself, clashing with the Turtles although it is mainly due to him being bored and interested in toying with the Turtles.
 * Oroku Saki/The Shredder (voiced by TBD) - the terrifying former head of the Foot Clan whose clan was ripped from his control thanks to the Turtles as he has been imprisoned for a year, now only wanting one thing after breaking out of prison, to make the Turtles suffer.
 * Simon Bonesteel (voiced by TBD) - a flamboyant big game hunter who sees mutants as the next big prey to hunt after, becoming interested in hunting them down. Eventually, realizing he needs a tactical advantage, he mutates himself into a tiger.
 * Dirtbag and Groundchuck (voiced by TBD and TBD, respectively) - two rather incompetent mutants who want to prove themselves as the best criminals of all time with Dirtbag being a mole that can dig massive holes and Groundchuck being a mutant bull with cybernetic enhancements.