Finn

Finn Ward, (or Pen, from the pilot episode) is the main protagonist of the series Adventure Time.

Background
As shown in "Memories of Boom Boom Mountain", Finn appears to have been abandoned during infancy, left alone in a woodland. He reveals that he made "boom boom" (in reference to bathroom jargon) on a large leaf, fell on it, and laid there until Joshua and Margaret (the mother and father of secondary protagonist Jake) rescued him from the wilderness. In "Henchman" when Finn is asked about his parents, he says Jake told him that he came from a cabbage, although he could've just been common joking.

Appearance
Finn is a 12 year old human with very thin limbs who wears a white hat, which he has proclaimed is "awesome", that covers all except his face with two "ears" sticking out on top. He also wears a blue short-sleeved shirt, blue-jean shorts, a backpack made up of two shades of green, which he rarely takes off, rolled-down white socks, and a pair of black shoes. When he's in the Ice Kingdom, he wears a yellow sweater. He has several missing teeth because "he bites trees and rocks and stuff", according to Pendleton Ward, the creator of Adventure Time. Ward has also stated that Finn is blonde. (As shown on one of the promos on Cartoon Network.)

Personality
Finn is brave and righteous, as he will slay only evil things, as revealed in "The Enchiridion!". He often shouts random phrases such as "Shmowzow" and "Slam-a-Cow", along with many other nonsensical terms. He is shown to be very hyper. He has a very strong sense of responsibility and gets upset when he is unable to help others. Finn also has a competitive side that is brought out by his friendship with Jake, leading to bets and new adventures like in the episode "Dungeon". He is also quite fearless as he is constantly faced with the task of killing many hideous beasts.

Abilities
Finn is proficient in several forms of combat, including hand-to-hand, magic, and sword fighting. He can also jump very high, as seen in many episodes. Finn has some origami skills, as shown in "Ricardio the Heart Guy" where he makes Princess Bubblegum a paper crane. Finn might still have the magic powers he gained in "Wizard", although he has not used them since. However, Pen Ward has stated on his formspring that all of the magic Finn had gained was contained in the robes he and Jake got, which were destroyed. He can auto-tune his voice, Because he says he swallowed a computer before the events of The Jiggler, and sings in "The Jiggler" and "Freak City". He can fold very far flying paper airplanes, as shown in "The Enchiridion". He is very good at playing a game called Adventure Masters, which he and Jake play on Beemo from time to time. Finn also can dance as shown in "The Enchiridion".

Relationships
Being a hero, Finn has become quite popular in the Land of Ooo, starting many quick friendly relationships.

Jake
Finn and Jake are best friends and will go out of their way to protect each other, no matter what. Finn becomes visibly angry whenever Jake is hurt or is presumed dead. This relationship existed from the start of the series. Jake seems to call him 'brother', bro" 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 wouldn't even try 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. At first Jake regretting 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 without her universal translator (she speaks Korean).

Princess Bubblegum
Finn has a rather obvious crush on Princess Bubblegum, often having fantasies about her saying things like, "You're so cute, Finn!" or even kissing him. 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.

Marceline
Finn's relationship with Marceline is clouded by the fact that Marceline is a "sexy vampire lady",

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.
 * In the episode "Ocean of Fear", Finn is revealed to have Thalassophobia, which is a fear of oceans or seas. Finn has no problem swimming in the episodes "Business Time", "My Two Favorite People", and "The Witch's Garden" because he has a specific fear of the ocean, and not small bodies of water such as lakes, rivers or wells.
 * In "Memories of Boom Boom Mountain", Jake reveals that Finn still cries when 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. In "The Jiggler", Finn uses his left hand to draw, so it appears that Finn is ambidextrous, which means that he can use both his hands with equal ability. Either that, or this is a continuity error.
 * His hat somewhat resembles Max's hat from Where the Wild Things Are. Also, the two 'ears' on his hat are portrayed as a cat's ears in FusionFall.
 * Finn and Jake gained magical abilities in the episode "Wizard", but they have never used those abilities in any other episode.
 * It is later said on Pendleton's Formspring that the all of the magic Finn gained in that episode was contained in the robes they got. The robes were later destroyed.
 * Finn and Jake can accurately tell what time it is by looking at how the sun affects the trees, stated by Pendleton Ward.
 * In the Animated Short, the hole in his hat is half of a circle, instead of a full circle in the cartoon.
 * Finn is probably going through puberty, as in some episodes his voice cracks, mostly when he screams. A good example of this is in the episode "Ocean of Fear".
 * Finn's last name is Ward, as in "When Wedding Bells Thaw", Ice King wonders if to himself if he is at the Ward household. The last name Ward belongs to the creator Pendleton Ward.
 * Confirmed on Pendleton Ward's Formspring, Finn has blonde hair.
 * Finn has a a crush on Princess Bubblegum, and whenever someone says "Finn," "Princess Bubblegum," and "crush" in the same sentence, he growls and blushes fiercely.
 * Apparently, Finn can play the flute, as seen in "Prisoners of Love", when he plays a little selection before throwing the flute at Ice King.
 * Finn refers to grapes as "purple whatevers" as seen in "The Jiggler".
 * Finn can sing in autotune as seen in "The Jiggler" (he sings Finn's Baby Song) and "Freak City" (he sings The Hero Boy Named Finn.) Finn reveals to Jake in "The Jiggler" that he has the ability to sing in autotune after swallowing a small computer.
 * In "Freak City", Finn claims he is "freakin' all about sugar". Yet, he also explains that he is even more all about feeding hobos.
 * Apparently, Finn has always had (or very close to always had) his "Awesome Hat". In the episode "Memories of Boom Boom Mountain" the viewer can see Finn as a baby wearing the same exact hat, except that it is a smaller size.