He is also the archenemy of Finn the Human and Jake the Dog. After resurfacing, the Lich murders Billy and resumes his scheme to destroy all of reality.

However, the Lich is years later released from his prison (unintentionally) by the Waving Snail. Years prior to the story, the Lich was defeated and sealed away by the Land of Ooo hero Billy. The Lich is an ancient undead sorcerer who is bent on eradicating all life in the multiverse until nothing but himself remains. He serves as the main antagonist of Seasons 2, 4 and 6, and the premiere arc of Season 5.

The Lich, also known as the Lich King, is the main antagonist of the Cartoon Network series Adventure Time. ~ The Lich's most famous quote as Sweet P