Skeletor is the tyrannical ruler of the dark side of Eternia, operating from his lair on Snake Mountain. He prides in his evilness and his perceived astuteness, and is usually ambitious but optimistic about his plans. He shows little tolerance towards failure and incompetence and usually gets mad at his minions when something goes wrong. He has mastery over magical powers which he learned from Hordak, and often carries around a magical weapon known as the Havoc Staff. Besides his advanced magic, he has also been depicted with technological knowledge to build various machines and contraptions; and is skilled at physical combat as well. He also has a purple felinoid pet named Panthor.
Skeletor's origins have been depicted differently in the various incarnations of the franchise. In the continuity of the 2002 series, it is shown that he used to be an evil Gar warrior named Keldor who lost his face in an accident when he attempted to attack Randor with acid; only to have the acid splash on the king's shield and hit Keldor instead. However, nearly all other sources, including the original series, simply have him coming from another dimension (Infinita) and the skull is just the natural look of his face. This is especially visible in the live action movie, in which it is clear that he is simply an alien whose face resembles a skull, rather than having an actual skull for a face. In the comics which follow the continuity of the original Filmation series, it has been implied that Skeletor was originally Keldor, King Randor's half-brother sorcerer who was of Gar ascendance (hence his blue skin) and gained his skeletal appearance as a result of being transported to Infinita, although the details are unclear.