Finn

Finn (known as Pen in the original short), or his full name Finn The Human, is a twelve-year-old boy who goes on adventures with his best friend, Jake. He wears his self-proclaimed "awesome" white hat everywhere. He often shouts random mathematical terms, such as "Algebraic!", despite the fact that in Slumber Party Panic, Princess Bubblegum revealed that Finn is terrible at mathematics. In the Animated Short, it was shown that Finn has feelings for Princess Bubblegum. Many princesses seem to like him or have a crush on him.

Appearance
Finn wears a white hat that covers his entire head, but leaves an opening for his face. He wears dark blue shorts and a plain blue shirt. He carries a green backpack on his back, and wears black shoes. When going to the Ice Kingdom, he wears a brown turtleneck. It has also been noticed that Finn has several teeth missing. In a few episodes, Finn is seen carrying a sword, with many dents and scratches. It is made with a yellowish metal, possibly bronze. He may be 5 feet tall or taller. He is rarely seen without his green bag.

Personality
Finn is a brave adventurer, even though he only fights creatures that are evil. In the episode The Enchiridion, he slays Heart Beast, but could not kill the neutral, harmless Ant. He blushes at a compliment Jake makes during the same episode. His face gets red when he is ashamed at himself or really furious. He often loses his temper when other people makes things harder for him and get in his way, such as Lumpy Space Princess and Tree Trunks. However, he apologizes to them during the same episode that he gets angry at them, which shows that he can be caring. Several girls flirt with him or try to kiss him, including Tree Trunks, Marceline, Slime Princess, Hot Dog Princess, and even a couple more. The only one that he harbors a deep crush on is Princess Bubblegum. Finn misjudges many people's adventurous skill. This was shown in Tree Trunks (episode) to Tree Trunks, My Two Favorite People to Lady Rainicorn, and to the Business Men in Business Time. He loves to dance and to have fun. He is very popular in the Candy Kingdom.

Abilities
Finn is proficient in Kung-Fu, as seen in the animated short. He is unable to swim, as shown in Ocean of Fear. He is able to do the science dance, which was introduced in Ricardio the Heart Guy. In the episode The Jiggler, it was revealed that he swallowed a small computer which gave him the ability to sing in auto-tune. He may also be good at origami, which is also shown in Ricardio the Heart Guy, when he makes a paper crane for Princess Bubblegum. He also can make an airplane, which was seen in The Enchiridion. He can snowboard on penguins, and has the fortitude to eat a broom, as seen in Wizard (episode). He keeps everything he needs for adventuring in his backpack. Things kept in it include: a sword, a flute, trail mix, grapes, a brown turtleneck, and a goblet. He broke his flute picking a lock to a sad ogre's heart, and broke it again in the episode Prisoners of Love. He can spit on a target over a long distance.

History
As mentioned in Memories of Boom Boom Mountain, the reason Finn is a hero is because one day when he was a baby he took a "boom boom" on a leaf and fell in it. As he lay there, crying, no one bothered to stop to help him with his problem. He also vowed that on that day, he would help anyone in need. Ever since then, he cries when he takes one. Like Flapjack from The Marvelous Misadventures of Flapjack, it is unknown who gave birth to Finn. Some of Finn's enemies are:
 * Ice King
 * Ricardio
 * Ogre
 * Dark Magician
 * Shark and Science Cat
 * Marceline, although occasionally friends
 * Tiffany

Jake
Finn and Jake are best friends and will go out of each other's way to protect each other, no matter what. Finn becomes visibly angry whenever Jake is hurt or presumably dead. This relationship existed from the start of the series. Jake seems to call him 'brother' and 'dude' often, showing that they share a brotherly relationship. However, Finn can get frustrated with Jake because of his laziness, shown especially in The Witch's Garden when Finn yells at Jake because he wasn't even trying to regain his powers. Finn has been frustrated with Jake before, such as in the City of Thieves when Jake, overpowered by the thievery of everyone around him, steals a pair of boots.

Lady Rainicorn
Finn became friends with Lady Rainicorn after Jake wanted to hang out with both of them at once. This backfired on Jake initially, but seems to have worked out in the end. Finn and Lady Rainicorn still share a close bond, despite the fact that Finn can't understand Lady Rainicorn without her universal translator.

Princess Bubblegum
Finn has a rather obvious crush on Princess Bubblegum, often having fantasies about her saying things like, "You're so cute, Finn!" The best proof of this is in Business Time, when Finn does an imitation of Princess Bubblegum in a high-pitched voice, accidentally revealing that he thinks her voice is attractive. He often blushes at things she says to him, as in the episode Ricardio the Heart Guy when, as a joke, Princess Bubblegum asked Finn to kiss her. Finn also got extremely jealous of Ricardio, who was hanging out with Princess Bubblegum more than he was comfortable with. He got so envious that he came up to Princess Bubblegum and Ricardio and interrupted a scientific conversation between the two to ask if Princess Bubblegum wanted to hang out with him, all the while doing the Science Dance to impress her. Finn denies that he was ever jealous, however, constantly making excuses and even shouting, "I'm not jealous! I'm WEIRD!" There was also a chapter in the Enchiridion dedicated to kissing princesses, and Finn blushed as he read it. The princess calls him by his full name (Finn the Human) in the episode The Enchiridion, which shows some evidence that their relationship may be a little formal, although this has only happened once and most of the time they behave like very close friends.

Marceline
Finn's relationship with Marceline is clouded a bit by the fact that Marceline is a vampire. At the beginning of the episode Evicted, Finn seemed to have interest in Marceline, though perhaps not romantically like his relationship with Princess Bubblegum. Fascinated with her powers and abilities, he seemed to want to be friends with her until she kicked them out of their own home. In the music montage for Evicted, the singer refers to Marceline as a "sexy vampire lady", though it is unknown if Finn feels this way. Finn has been known to blush around Marceline, especially when she kissed his cheek. He soon gets over this embarrassment though, and seems to be frightened of her more than he is attracted to her. Finn and Marceline share a friend/enemy relationship.

Quotes
See Finn/Quotes

Trivia

 * In the pilot episode/short Finn was named Pen, a name he got from the show's director and producer, Pendleton Ward.
 * In the pilot, Finn is voiced by Zack Shada. However, in the series, he is voiced by Zack's younger brother, Jeremy Shada.
 * Even though Finn can't swim in the episode Ocean of Fear, he was seen swimming in a lake in the episode Business Time and My Two Favorite People. This may only be because he has a specific fear of the ocean, and not small bodies of water such as lakes.
 * Jake says Finn cries whenever he poops.
 * Finn's hat has a small resemblance of Bueno the Bear from "Barrista" (a short from Pendleton Ward).
 * Finn is left-handed when writing or drawing, but uses his sword with his right hand. In Business Time, he used his sword with his left hand for a short period of time, and then switched back again.
 * His hat somewhat resembles the boy's hat from 'Where the Wild Things Are'. Also, the two 'ears' on his hat are portrayed as a cat's ears in Fusionfall.
 * Because it was never proven that Finn and Jake got their magical abilities (Wizard) taken away from them, both Finn and Jake still have their magical abilities.
 * Pendleton Ward himself stated that Finn's full name is Finn The Human, meaning Finn is his first name, The his middle and Human his last name.
 * Finn and Jake can accurately tell what time it is by looking at how the sun affects the trees, stated by Pendleton Ward, the creator of Adventure Time.
 * In the Animated Short, the hole in his hat is half of a circle, instead of a full circle in the cartoon.
 * Finn's voice cracks frequently, providing the evidence that he is going through puberty.