Valeena

Valeena, better known as the Skull Sorceress and the Skull Witch, is an evil witch and her first appearance is in The Savage Lands Part 2. She kidnaps Jinmay and is going to sacrifice her to the Skeleton King Worm but the Monkey Team interferes, frees Jinmay, and knocks Valeena off the temple edge and she falls into a pit of ooze, seeming to kill her. She returns in later episodes near the end of the series run as one of the main villains, and when the team returns to Shuggazoom in Ghosts of Shuggazoom. She is behind everyone turning into zombie like ghosts, but she's defeated again and trapped inside of a necklace that Mandarin wears in the Night of Fear to show the Monkey Team's true fears. It's revealed in one of the episodes that she's brought to the Skeleton King as a disciple to him and he turned her into the skull sorceress as a young child, and her whole goal is to resurrect Skeleton King after his defeat. She succeeds along with Mandarin, but as a token of gratitude, Skeleton King blasts her into ash.