1x5 - Adventure Time - Mini Series “Stakes!”

While on the trail of the vampire known as the Moon, the group run into trouble when the shape-shifting Hierophant finds them. He proves to be too powerful to fight, so on learning that he cannot enter houses without permission, Jake shapeshifts into a house and the group take shelter inside. The Hierophant proposes joining forces against the Vampire King, and Marceline agrees on the condition that the Hierophant stops drinking blood. However, he attacks her and during the struggle, he is accidentally knocked into Jake and dies due to entering a house uninvited. Marceline reabsorbs his shapeshifting powers but then falls ill, having been poisoned by the Hierophant's stinger.