Finn

Finn Mertens (full title: Finn the Human, or formerly known as Pen) is the main protagonist of the series Adventure Time. He is voiced by Jeremy Shada.

Appearance and equipment
Finn is a teenaged human. He was roughly five feet tall at the show's debut, but sometime between "The Cooler" and "The Pajama War," he underwent a growth spurt and is currently almost the height of Princess Bubblegum. He is missing several teeth due to his habit of biting trees and rocks among other things.

Although his eyes typically lack detail and appear as small black dots, they are shown to have color in "The Enchiridion!" while Finn is under going Dark Magician's trials. His left eye is green while his right eye is blue, characteristic of the genetic condition heterochromia. However, as stated by lead character designer Andy Ristaino, "That was a special occasion. The heterochromatic effect was a byproduct of him being hypnotized by that guardian dude." He went on to confirm that both of Finn's eyes are blue.

Finn's weight seems to fluctuate between episodes, with him seeming chubbier in some instances than others. Pendleton Ward stated on the "In Your Footsteps" commentary on the Season 4 DVD that his weight depends on how active he is adventuring, along with his diet, so it often changes.

In "Escape from the Citadel," Finn's right arm is actually torn off, and then coated by the blood of a Citadel Guardian, which grows a small flower. He later got his arm back in the episode, "Breezy," where the flower stub matured into a tree and broke away like a cocoon, revealing a new limb, with a green thorn protruding from the palm. This thorn was later revealed in "The Comet" to be part of the Grass Sword sticking out from his skin, as his new arm was made of grass.

Finn has blonde hair which is first seen in "To Cut a Woman's Hair," where Finn removes his hat, and long, golden locks of hair flows out. His hair has a glowing sheen and extended his body length, until he cuts it off and gives it to the Tree Witch. His hair slowly begins to regrow throughout several episodes until "Another Way where it has grown to his shoulders." By "The Lich," Finn has grown his hair slightly longer than in its appearance in previous episodes. However, in the episode "Davey," Finn has shaves off almost all of his hair for the second time so he can disguise himself as 'Davey', but begins to regrow it in "Little Dude," and the episodes after it. In "Puhoy," an adult Finn is shown to have grown facial hair and his hair become curly although since that part of the episode was a daydream it may not be 100% accurate. In "May I Come In?", Finn's long hair is shown to have grown back to around the length it was in "To Cut a Woman's Hair", when Finn takes of his hat while acting as bait to lure out The Hierophant.

Finn typically wears a munsell blue t-shirt, denim shorts, a two-colored lime green circular backpack, rolled-down white socks, and a pair of black shoes. Finn's most prominent attire is a white hat with two "ears" (which Joshua calls "nubs") sticking out on top that covers his entire head minus his face. The hat is inspired by a character called Bueno, a bear from a Pendleton Ward comics. Finn can occasionally be seen in variations of his standard outfit. In "Ocean of Fear," his footwear appears to be black booties with white cuffs. In "It Came from the Nightosphere," Finn has a small pocket sewn onto his shirt that he carries Jake in. This appears again in "Davey" where he uses it to hide Jake while Finn steals the keys from the guards as he breaks the former out of jail. During "In Your Footsteps," the Bear wears Finn's clothes, which suggests that Finn has multiple sets of the same outfit, including his hat. However, in "Little Dude," when Finn's hat comes to life and is set free, Jake tells Finn, "Okay, let's go skin an evil bear," which may imply that Finn only had one hat.

Aside from his normal outfit, Finn can be seen wearing a cream-yellow sweater in colder areas such as the Ice Kingdom but currently wears his pink sweater made by Princess Bubblegum. In "Holly Jolly Secrets Part II," he wears a dark blue sweater with Christmas decorations on it and a green scarf. Finn also wears white briefs that make their first appearance in "City of Thieves" when Penny steals his shorts at the end of the episode. In "Who Would Win," he was shown to wear a different pair with red elastic. Finn sleeps in red footie pajamas that appear in many episodes, but in the animated short, he sleeps in a red sleeping bag in his regular clothes. In the series, the sleeping bag is beige.

Finn has had a total of five major swords, plus temporary borrowed ones. (1) He originally favored Scarlet, the Golden Sword. After being first turned into a 4-D Sword and then destroyed by a black hole in "The Real You," (2) Finn is shown using the Root Sword (having a pink/silver blade and a red, twisted "root" handle) as seen in "Mystery Train." Along with this sword, his backpack has a new side strap that can hold the sword while walking. (3) In "Dad's Dungeon," Finn and Jake venture into Joshua's dungeon, built by Joshua to toughen Finn up. There, Finn retrieves the Demon Sword, which uses now as primary weapon. (4) After being first turned into the Grape Sword and then forced to destroy it in "Play Date," he replaces his weapon with the Grass Sword, as seen in "Blade of Grass." However, this too was lost, along with his right arm, after Finn's encounter with his father in "Escape from the Citadel." There have been a number of other swords used by Finn, but all were used only for a short period of time. (5) After Finn's grass sword was destroyed, he acquired the Finn Sword in "Is That You?" It was created by interacting with an alternate Finn from the past, creating a paradox. Finn uses this sword first in "Dentist."

Personality and traits
Although at times violent and aggressive, Finn is a brave and righteous boy. His aspirations to become a great hero makes him somewhat of a moral sheriff in the Land of Ooo, as he is willing to help and protect any innocent person or creature. Finn has a very strong sense of responsibility and becomes upset when he is unable to help others. Due to this and being somewhat simple-minded, Finn often feels conflicted when it is unclear whether something is good or evil as exemplified by his dealings with Marceline in the episode "Henchman." Despite his heroic nature, Finn also takes a liking to a "normal life" without any recognition or praise for being a hero and demonstrates this in "Davey."

Finn is also almost incapable of doing anything evil or unjust, and will struggle greatly against doing such things, as seen in several episodes such as taking part in thievery in "City of Thieves" or killing a neutrally aligned ant in "The Enchiridion!." However, Finn undergoes a slight change in "Wake Up" after he realizes that his father, whom he had high hopes of being a great hero, is nothing more than a selfish criminal. This, coupled with the loss of his favorite arm and sword due to his father's selfishness, pushes Finn to the point of wanting revenge. This is shown in "The Tower," where he attempts to go into space by building up a tower so that he could find his father, punch him, and take his arm. However, in the end, Finn learns to control his feelings of revenge with the help of Princess Bubblegum.

While he portrays himself as a rough and tough hero, Finn has a tender side that is capable of love and compassion, as shown by his boyhood crush on Princess Bubblegum and his brotherly relationship with Jake. Finn is also able to act like a gentleman when it comes to ladies. However, Finn seems to hate romantic scenes to the point of vomiting as seen in "Go With Me." However, Finn demonstrates growth in accepting romance and physical love as he willingly kisses Princess Bubblegum in "Too Young" and his latest ex-girlfriend, Flame Princess, in "Burning Low." His tolerance is seen again near the end of "Dream of Love," as he is no longer disgusted by Tree Trunks and Mr. Pigs' passionate kissing. Finn's care for his friends makes him very protective of them as demonstrated when Tree Trunks almost gets killed in the episode "Tree Trunks" and Jake in "The New Frontier." Overall, Finn is a very kind and selfless person who is always putting the safety of others above his own. Jake comments on his adopted brother by saying that "he is a good kid with a kind heart."

In the episode "Rainy Day Daydream," it is shown that Finn believes that "imagination is for turbonerds who can't handle how kick butt reality is" and that he finds real life to be better than anything imaginary. Finn then refuses to use his imagination until he has to reactivate Jake's "bombastic personality" in his imagination land, (which was just a basic gray and white empty plane hinting that Finn is not very imaginative). However, this is disputable when the gnomes harness the energy from Finn's imagination in the episode "Power Animal" despite it being inhabited with a few dainty creatures such as Bellamy Bug. The gnomes state that Finn's imagination is powerful enough to effect the real world (like Jake's but to a lower degree) and turn on Jake's imagination.

Finn can also be very stubborn; such as in "Memories of Boom Boom Mountain," "Wizard," "Dungeon," "Rainy Day Daydream," and especially in "Another Way." This is likely a reason why Finn is often determined to work without taking the easy way out as seen in "Business Time" and "The Real You." Finn can also be easily tricked, as in "The Eyes" when Jake convinces him that the giant hawks would take the horse to a land of sunshine and love stuff and take care of him. He can get overly angry and yell as in "Trouble in Lumpy Space" and "Tree Trunks," but immediately feels guilt and remorse and apologizes when he can. Finn is also quick to try and resolve problems that he may have caused, such as when he caused Flame Princess to get hurt by the Ice King. Finn is also empathetic and this was developed when he was an infant since no one (except Jake's parents Joshua and Margaret) helped him.

As a courageous warrior and a fearless thrill-seeker, Finn enjoys putting himself in the midst of danger simply because he enjoys a challenge as shown in "Jake Suit." However, he is also shown to have several fears. In "Another Way" and "King Worm," he demonstrates a fear of clowns. Also, in "King Worm," he shows a fear of Bubblegum calling him too young. In both "King Worm" and "Ocean of Fear," Finn has an unexplained phobia of the ocean, or thalassophobia, despite the fact that he can effortlessly come into contact with any other body of water. Other fears that Finn has are the Ghost Lady, King Worm, and the Lich. Finn's fears change in "Billy's Bucket List," after he destroys Fear Feaster, a manifestation of his fears, with his grass sword while attempting to go into the ocean to fulfill Billy's wish. The Fear Feaster's death seems to have eliminated all of Finn's fears, or at least his fear of the ocean.

Despite being mischievous from time to time, Finn is a very kind-hearted person. It's shown multiple times that he shows clear concern for others, even for those who have willingly hurt him, such as in The Enchiridion, he returned to the giant his dollar (note that this was was the very same giant who ate his beloved brother Jake and even kept insisting that he was dead). Furthermore, he shows clear contempt for anything that is done out of immoral reasons.