The Gauntlet of the Hero

The Magic Gauntlet is a mystical weapon that is able to harm, and slay, The Lich. Princess Bubblegum gives it to Finn to go and slay The Lich with. It is unknown how she got it. The gauntlet was destroyed during Finn's battle with The Lich.

Appearance
The Gauntlet is gray with blue-ish fingers. There are metal bands all over it. There is a blue gem attached to its wrist. On the top of the hand is an eye.

Trivia

 * The gauntlet was seen to be used by Billy during all of his adventures in the past. He has been shown to not possess it by the time Finn meets him in His Hero. (though it could be due to being hidden amidst the clutter in Billy's cave)
 * The eye on the top of it could represent the all seeing eye, which is said in ancient culture to see everything.
 * Like Billy himself, the gauntlet has six fingers as opposed to the typical four fingers nearly every other human and humanoid in Ooo possesses.
 * The gauntlet seems to possess some degree of life & sentience, as it shed a tear when Finn hit it in the eye to make it stop firing a magical blast & wouldn't work for him again until he apologized.
 * Strangely, Billy wears the Gauntlet on his left hand, while Finn wears it on his right. It is possible that two Gauntlets were forged and at one point at least intended to be worn as a pair.