In the episode ' The Lich,' The Lich disguises as Billy and got Finn and Jake to help him create a portal to another galaxy. In ' King Worm,' he is seen drinking coffee with Princess Bubblegum, where she tells Finn that adults are talking, making Finn freak out. In the episode ' In Your Footsteps,' he is seen taking The Enchiridion from the bear, when he is possessing the Snail. But he was defeated and Princess Bubblegum was revived, but became 5 years younger in the process. After Finn got her loads of toxic chemicals, without Finn realizing, Bubblegum soon turned into a demon monster where Lich could get a good opportunity to remove all life from Ooo. The Ice King saw The Lich enter PB's body, but he doesn't know if it was really him because of his Wizard Eyes. In the episode ' Mortal Recoil,' The Lich possesses Princess Bubblegum after Ice King 'accidentally' dropped her into the acid. The snail cracked the amber stone and set the Lich free. In the episode ' Mortal Folly,' it is explained by Princess Bubblegum that Billy imprisoned Lich in a large amount of amber, but while Princess Bubblegum was explaining the story of The Lich to Finn and Jake, The Lich possess the waving hidden snail. His main goal is to remove all life from the Land of Ooo.

He can also possess other people, however, this can be countered by wearing a tiara, a special sweater (such as Finn's Like Like Sweater) or anything that has a mystical gem that causes them to be 'immune' to The Lich's possessive powers.

It can also increase the power of his attacks, though, this hasn't been fully proven. He gains his power from the Well of Power, which gives him his powers. The Lich has the power to summon green flames from his hands. Lich is a magical undead sorcerer that can cast many different spells to cast off foes. His species is from the species known as Lich. The Lich is an undead villain that first appeared in the episode ' His Hero,' where Billy punches him with The Gauntlet of the Hero Billy.

Adventure time lich