Billy

Billy is a character in Adventure Time who appears in "His Hero". Billy is Finn and Jake's idol, in terms of adventuring. Thus, the two are immense fans of his.

As described in Billy's Song, when he was younger, Billy was a hero of action much like Finn. He is known to have rescued a princess from Fire Count, slain an evil ocean, and fought against a giant bear. Perhaps most importantly, he's also said to have defeated The Lich. When The Lich escaped, he could have either defeated him or lost due to his old age.

When Finn and Jake finally meet him, he is old (his red hair turned white) and he frowns upon violent heroism like theirs. He hated the futility of fighting evil when more would always pop up later, so he chose to help people directly through non-violence. He apparently even had his own magical dog, though it is apparently deceased, seeing as he keeps its skeleton in his cave. Finn and Jake wind up trying to follow his example of pacifism, but end up returning to their violent ways, apparently with Billy's blessing.

Appearance
He is very tall, and has a long beard and long hair which looks like that of a caveman's. Each of his hands has six digits: 5 fingers and 1 thumb.

He bears a strange scar that looks like he had stitches on his left shoulder. During his younger days, he possessed a gauntlet with a jewel on the wrist and an eye on the top of the hand, which he used for combat, including and most importantly during his battle with The Lich. He also appears to have a magic sword called "Nothung" which he can summon by calling it's name. He has also lost his hair and gone bald in his old age.

Trivia

 * In earlier versions of the storyboard, Billy was named "Hogarth".
 * In earlier versions of the storyboard, Billy dies and comes back as a ghost.
 * Billy's sword is named "Nothung" after Sigurd's sword in Richard Wagner's cycle of operas Der Ring des Nibelungen (The Ring of the Nibelung). Billy has the ability to call his sword by saying its name. He retains the ability to do this even when he is old, even though it first appeared to do so because of the gauntlet on his left hand.
 * Billy is voiced by Lou Ferrigno, who also played The Incredible Hulk in the live action TV series from the 1970s.
 * Coincidentally, the actor who played the Hulk's human form on the show had a "Billy"-like name: Bill Bixby.
 * Unlike most characters on the show, who possess four-finger hands, Billy's hands have six fingers.
 * Billy's appearance in the "His Hero" titlecard is based on Frank Frazetta's painting "Death Dealer."
 * Like Finn and Jake, he keeps a lot of treasure in his home.
 * Billy's name and heroic attributes may be a reference to the song "Billy Don't Be a Hero", originally recorded by Paper Lace but also made famous by Bo Donaldson and the Heywoods.
 * He was the one who imprisoned The Lich in his lair, as he was said to have defeated him in the past.
 * According to Adam Muto, a storyboard artist, Billy will be back later in Season Two.
 * This never came to be, as Billy was only mentioned in the season finale, but made no appearences.
 * By touching Billy's sword (found outside his cave), a crack opens in the wall, leading to his home.
 * The gauntlet he wore when he was young is really the The Gauntlet of the Hero Billy, which is the only weapon that can hurt The Lich.
 * According to Adam Muto, Billy is still strong, but not as strong as he once was.
 * Also stated on Adam Mutos formspring is that Billy could have defeated Marceline when he was younger.