As shown in "Memories of Boom Boom Mountain," Finn appears to have been abandoned in a woodland during infancy. He reveals that he made "boom boom" (a reference to scat) on a large leaf, fell on it, and lay there crying untilJoshua and Margaret (Jake's parents) rescued him from the wilderness to raise him alongside Jake, who becomes like a brother to him (as such, Jermaine is also Finn's adoptive brother). In "Memory of a Memory" a baby Finn is seen singing his Baby Finn Song in the bathroom of what appears to be Joshua and Margaret's house. In "Henchman," when Finn is asked about his parents, he says Jake told him that he came from a cabbage, in jest. In "Susan Strong," Finn states that he knows nothing of his human parents or any other humans.
Finn may be the last true human in the Land of Ooo, or possibly the world. In the episode "Her Parents," Lady Rainicorn's mom says she thought humans were extinct. This lends new significance to his title "Finn the Human," as his humanity may be unique in Ooo.
Up until "Susan Strong," Finn believes he has never met another human. Finn becomes morose and "soul-searchy" when he thinks about it. In the same episode Finn encounters Susan Strong. Even though the other members of Susan's tribe of Hyoomens were revealed to be mutants, Susan's identity as a human or mutant is left ambiguous. Other "human" characters (such as Penny or the Old Man Henchman) have been confirmed by the show's creator, Pendleton Ward, to be mutants orhumanoids.
Note that Fionna (the female version of Finn) is also a human however she was just a character in Ice Kings fan fiction.
Pen, Finn's original art designFinn's Magical Hair:Main article: Finn's hat
Finn is a 13-year-old human. He has very thin, noodly limbs and wears a white hat with two "ears" sticking out on top, which he has proclaimed to be "awesome." His hat covers his entire head, except for his face. He also wears a light-blue T-shirt, denim shorts, a green backpack, rolled-down white socks, and a pair of black shoes. When he's in the Ice Kingdom, he occasionally wears a yellow sweater. He has several missing teeth because he bites trees and rocks among other things. He has also eaten a broom in the episode "Wizard."  Ward has also stated that Finn has blonde hair which can be seen in "To Cut a Woman's Hair," where Finn removed his hat (one of three times he has done so), and long, golden locks of hair flowed out. His hair had a glowing sheen and extended his body length, until he cut it off and gave it to the Tree Witch. His hair subsequently began to regrow, as shown in "Mortal Folly" and in "Heat Signature." He wears white briefs that made an appearance in "City of Thieves," when Penny stripped him at the end of the episode.
Although his eyes typically lack detail and appear as small black dots, they are shown to have color in the episode "The Enchiridion!," when Finn is tried by the Dark Magician. His left eye is green while his right eye is blue, characteristic of the genetic condition heterochromia. (But as stated by Andy on Formspring,"That was a special occasion. The heterochromatic effect was a byproduct of him being hypnotized by that guardian dude."Andy Ristaino confirmed that Finn's eyes are blue.
Although Finn has wielded all number of weapons, he originally favored a gold sword. As of the episode "Mystery Train," Finn is shown using a new sword with a pink/silver blade and a red, twisted "root" handle. (Finn's original sword was destroyed by a black hole in "The Real You.")
Though at times violent and aggressive, Finn is a brave and righteous hero. He has a very strong sense of responsibility and gets upset when he is unable to help others. He is almost physically incapable of doing anything evil or unjust, and will struggle greatly against doing such things, as seen in several episodes such as"City of Thieves," "The Eyes," and "The Enchiridion!" Even though he acts like a normal boy, Finn acts like a gentleman when it comes to ladies.
Finn is shown to be a fearless thrill-seeker and enjoys putting himself in the midst of danger simply because he enjoys a challenge. However, as illustrated in "Ocean of Fear," Finn has an unexplained phobia of the ocean, orthalassophobia, which may be explained in a future episode, despite the fact that he can effortlessly come into contact with any other body of water. While he portrays himself as a rough and tough hero, Finn has a tender side capable of love and compassion, as shown by his boyhood crush on Princess Bubblegum and his brotherly relationship with Jake. However, Finn seems to hate romance movies and kissing because in "Go With Me" he actually vomits during a kissing scene in a movie.
His aspirations to be a great hero make Finn somewhat of a moral sheriff to the Land of Ooo, as he is willing to help and protect any innocent creature in his strange world. Finn appears to be somewhat simple-minded, seeing that he gets a lot of conflicting emotions when it's unclear whether something is good or evil (exemplified by his dealings with Marceline in the episode "Henchman.")
Finn is proficient in several forms of combat, including hand-to-hand combat, magic, and swordsmanship. He can jump very high and is exceptionally strong and agile for a boy of his age. Despite his age and appearance, Finn seems to be quite strong and athletic; he can be seen wrestling full-grown Marauders, the large grass ogre Donny, and a general variety of monsters and creatures several times his size. Finn is also capable of lifting up Princess Bubblegum, as shown in Mortal Recoil when he picks her up and puts her in her bed. He also can make his arms and legs bend in inhuman ways, as during the Science Dance and when he uses "spaghetti limbs" (waving his arms and legs, which Jake can also do).
Besides combat, Finn has displayed many other impressive abilities in handicraft. He has some origami skills, as shown in "Ricardio the Heart Guy," in which he makes Princess Bubblegum a paper crane. Finn is also somewhat gifted at constructing simple machines, such as the catapult in "The Witch's Garden." Finn writes and draws with his left hand and occasionally with both hands at the same time. He additionally handles his sword with his right hand, suggesting he may be ambidextrous, able to use both hands with equal skill.
Finn enjoys singing; after swallowing a tiny computer, he gained the ability to auto-tune his voice on command, although he can sing without auto-tune as well. Apparently, Finn can also play the flute, demonstrated in "Prisoners of Love," in which he played a short lick before javelin-throwing it at Ice King. Unfortunately, the flute unraveled before it could hit him, and Finn has not played the flute in any episode since.
Finn is very good at playing a video game called Adventure Masters, which he and Jake play on Beemo from time to time. He can also spit very long distances, as demonstrated in "Evicted!," when he spits on Marceline and in "My Two Favorite People," when Finn spits on Tiffany's face. In "Dungeon," one of the trials that Jake says Finn would have breezed through is a spitting competition against a goblin-like creature.
Finn and Jake gained magical abilities in the episode "Wizard," but they have never used those abilities in any other episode. Pendleton Ward later revealed on his Formspring that all of the magic Finn and Jake gained in that episode was contained in their robes, which were destroyed.
Likewise, in "The Chamber of Frozen Blades," Finn and Jake gain ice-ninja skills, but it's unlikely they will use them again because, according to Adam Muto, "They didn't have enough time to commit the incantations and hand positions to memory."
As both housemates, and best friends, Finn and Jake share a very deep and strong bond. Having been raised together by Jake's parents, the duo have a relationship similar to that of siblings, with Jake acting as Finn's older brother. Though they have an unconditional love for each other, Finn can get frustrated with Jake because of his laziness and lack of motivation, shown especially in "The Witch's Garden." As a more laid-back character, Jake often tries to relax Finn's fiery personality in the face of a struggle, advising him not to worry in most situations. Though he sometimes leads Finn down the wrong path, Jake genuinely means well for his companion and is usually an encouraging and protecting figure in Finn's life. Finn and Jake have saved each other's lives on several different occasions, and often adventure throughout the Land of Ooo together.
Lady Rainicorn, Jake, and Finn===Lady RainicornEdit===
Finn became friends with Lady Rainicornafter Jake wanted to hang out with both of them at once in the episode "My Two Favorite People". At first Jake regretted introducing the two, but in the end he was glad it happened. Finn and Lady Rainicorn still share a close bond, despite the fact that Finn can't understand Lady Rainicorn's fluent Korean.
Bubblegum kissing FinnBubblegum and Finn create chemistry (literally).Finn and PB kissing.===Princess BubblegumEdit===
Finn has a rather obvious crush, which he denied before the events of the episode Wizard Battle, on Princess Bubblegum, whom he occasionally calls "Peebles" out of affection. He is known to interact with her more than any of the numerous other princesses of Ooo, and will jump at the chance to do anything for her. Finn becomes very protective and jealous when someone else comes between them, as seen in "Ricardio the Heart Guy," in which he sought to one-up Ricardio (obnoxiously performing the Science Dance as a desperate ploy to attract Princess Bubblegum's attention) and expose him as a villain. Though the princess is seemingly oblivious to Finn's affection, she often calls on him for any royal need. In "The Real You," Princess Bubblegum kisses Finn on the cheek, and he faints a moment after the kiss.
Finn always eagerly hopes to win the princess over with his heroic deeds. Finn and Princess Bubblegum share a staunch sense of morality and often work together to bring justice and balance to the Land of Ooo. Taking several dangerous and tomboyish cues from Marceline in "Go With Me", Finn tries to set up a movie date with PB, who banishes Finn from the Candy Kingdom until he stops "acting like a psycho."
In "Mortal Folly," when Finn and Jake are chasing the Lich King, the Ice King persistently nags them to give him their blessing to marry PB. When the Ice King says "it's not like you want to marry her," Finn blushes and angrily throws a rock at him, implying that he does want to marry PB. Earlier in the episode, before embarking on their pursuit of the Lich King, Princess Bubblegum gives Finn a pink, heart sweater that she knitted for him. This sweater would later protect Finn against the Lich using the "power of liking someone a lot," as Finn put it. (He later refers to the sweater as his "like-like sweater.")
In "Mortal Recoil," Finn outwardly confesses to the princess that he "likes her a lot", although it is unknown whether she actually heard him, as she was still possessed by the Lich at the time. Princess Bubblegum, whose incomplete reconstruction at the end of Season 2 (resulting from the candy surgeons' inability to completely recover all the pieces of her bubblegum body) caused her to revert to her 13-year-old self, hugs Finn after her recovery and calls him "Hero." They share a kiss in "Too Young." However, his grip on the princess' heart loosens after her re-ageing and she can only remember the hug (though she was joking, as confirmed by Natasha Allegri). Finn feels beaten afterwards, but a pep-talk from Jake brought his spirits back up. Finn got a kiss from Princess Bubblegum again after winning the wizard battle where she kisses him and then slaps him for cheating.
Finn and Jake's first meeting with Marceline.Marceline's first kiss for Finn.===MarcelineEdit===
Though an enemy in her debut, "Evicted!," Finn quickly befriends Marceline the Vampire Queen, as he learns that her seemingly evil ways are just playful teasing. A rowdy and adventurous character, Marceline and Finn share the same vigor and thirst for danger. As previously stated, Marceline loves to mess with Finn's head. Despite Jake's fear of Marceline (and of all vampires), Finn enjoys spending time with her so that they can be "awesome together." In "Go With Me," Finn asks her to go to "Couples-Only Movie Night," but only as a friend. Being (mutually) disgusted to the point of vomiting by the idea of kissing, Marceline has no interest in dating Finn.
Finn Beating the tar out of Ice King. Notice Jake playing his viola.===Ice KingEdit===
As the story's recurring antagonist, Ice King and Finn are frequently at odds. Finn is prone to impatience and quick aggression around him but can show him sympathy, as in "When Wedding Bells Thaw." However, Finn's aggression never outweighs his compassion, honor, and respect for life, as evidenced when he refused the opportunity to slay Ice King as Billy had slain the Fire Count. Similarly in "Mortal Recoil," Finn, albeit grudgingly, trusted and united with Ice King against their common enemy of the Lich-possessed Princess Bubblegum. Further contributing to their differences, Ice King competes with Finn for Princess Bubblegum, until the closing scene of Season 2. This mutual attraction for PB can be clearly seen in "Mortal Folly," where Ice King continually pesters Finn for consent to wed PB. Upon Ice King's saying, "it's not like you wanna marry her," Finn blushes and hurls a rock at Ice King. Ice King, however, loses interest in PB after her second revival, which reduces her age to 13. But with the events of "Too Young," Ice King will probably hunt Princesss Bubblgum again. Sure enough, he did in "Wizard Battle."
Oddly enough, Ice King does not seem to really hate Finn and Jake, as he only fights with them because they are opposing each other in terms of morals. He once tried to be friends with them (in his own, misguided way) and has willingly made alliances with them.
Magic Fist is the alter-ego of Finn and Jake that first appeared in "Wizard Battle." He's not a real wizard; he only entered Wizard Battle to save Princess Bubblegum from having to kiss Ice King for the prize was a kiss from her on the lips. He wore a blue eye mask, a cyan hood, and a large red robe. Finn was the head, while Jake was the body. See the gallery section for more images.
In the pilot, Finn is voiced by Zack Shada. However, in the series, he is voiced by Zack's younger brother,Jeremy Shada.
As of "Mystery Train" (an episode that Finn has a birthday in) he has aged and is now 13 years old, as confirmed by both Natasha Allegriand Adam Muto. The date of his birthday is June 18.Oddly enough, this means he shares the same birthday with Princess Bubblegum.
Finn technically is still the King of the Goblins; the goblins believe his scapegoat, Whisper Dan, to be him.
One of Finn's catch-phrases is being "all about" something. In "Freak City," Finn says he is "frickin' all about sugar". Yet, he also explains that he is even more "all about feeding hobos." In "The Real You," Finn shouts "I'm all about stupid!"
Finn is very tolerant of pain; although in "Crystals Have Power," he cries slightly when Jake pinches him and may have later "cried silently into his pillow for thirty minutes."
Finn and Jake frequently use math terms for catch-phrases (e.g. mathematical!, rhombus!, algebraic!). Since Finn is "terrible at math," it is possible that Finn does this to impress Princess Bubblegum, who is an avid scientist and mathematician.
Finn's favorite color is baby blue "boy style" as revealed in "The Silent King."
When Finn is wearing his doctor suit in "His Hero," he has three Scientific Parasites in his pockets. This is ironic considering Princess Bubblegum, who is smarter, only has one scientific parasite in her lab coat.
Finn's favorite food is meatloaf, as stated in "Still."
Finn appears as a playable character on Cartoon Network's TKO where his special moves are Look Out Below (when Jake falls on your opponent) and Sidekick Swing (when Finn grabs Jake's paw and Jake swings him at the opponent) and his super move is when Jake falls onto the opponent with an axe.
Finn, Jake, Bubblegum, Lady Rainicorn, Ice King, Stanley the watermelon, and the Reaper are characters in the game FusionFall, in which the player helps Finn save two princesses, get shirts from Stanley, and train with Finn in the petting zoo (Generator Rex).
Like most of the main characters, Finn is an Exosuit in the game Project Exonaut.