What is "skeletor"

Skeletor is a fictional character and the primary antagonist of the Masters of the Universe franchise created by Mattel. He is the archenemy of He-Man. Depicted as a muscular blue humanoid with a purple hood over his yellowing bare-bone skull, Skeletor seeks to conquer Castle Grayskull so he can obtain its ancient secrets, which would make him unstoppable and enable him to conquer and rule Eternia but his incompetent henchmen's stupidity always gets in the way.

In the 2002 series, Skeletor was once a man named Keldor whose face accidentally got splashed with a corrosive liquid. He survived, but at the cost of his face.