The Snail is a character that is hidden in every episode of Adventure Time. His cameos are like a running gag. In the episode Mortal Folly of Adventure Time, The Lich possesses the Snail and uses it to escape containment in the amber prison. From that moment it was looking like in this fanart Adventure Time Snail Sticker. Later in Mortal Recoil, the Lich possesses the Snail again after releasing Princess Bubblegum from his control.