Skeletor is a character in the Masters of the Universe franchise, the arch-enemy and main antagonist of He-Man. Tagged "The Evil Lord of Destruction", he is the greatest threat to present-day Eternia. Depicted as a muscular bluish humanoid with a purple hood over his yellowish bare-bone cranium, Skeletor seeks to conquer Castle Grayskull so he can learn its ancient secrets, which would make him unstoppable and enable him to conquer and rule all of Eternia. In the original minicomics and in the Filmation series, Skeletor is said to be an evil demon from another dimension. A later Mattel minicomic implies that he was once Keldor, brother of King Randor. The Mike Young Productions series confirms that Skeletor was once a man named Keldor, though no familial connection to Randor is ever established.

1987 Live action Masters of the Universe film:

In 1987, Cannon Films released a feature film version of Masters of the Universe. The role of Skeletor was played by acclaimed actor Frank Langella, who arguably gave the best performance in the film, and in the opinions of some fans, this was the best overall depiction of Skeletor. Famous voice artist and writer, Bryan Pyle tried but failed to procure the voice acting job of Skeletor originally, and eventually was forced to do sound effects and lesser voices on the show.

Due to the film's PG rating, this Skeletor was given license to be much darker than his cartoon counterpart ever could. At one point he casually incinerates one of his henchmen as punishment for failing him. The film abandons the campy connotations of Skeletor and gives him some measure of depth, which had been absent before. A glimpse of this occurs when the villain tortures a captive He-Man. Leaning in close to the hero, he inquires "Tell me about the loneliness of Good, He-Man... Is it equal to the loneliness of Evil?"

Langella's Skeletor is clad in more regal-like attire than is traditionally seen. Rather than dark purple, he wears all black, and his costume is less scant, covering his entire body with a robe and a flowing cape.

This version of Skeletor is also able to achieve what his previous incarnations could not. He unlocks the powers of Grayskull and becomes a living god. As he receives ultimate power Skeletor makes a dramatic speech worthy of the culmination of his life's evil dreams.

Imbued with cosmic power, Skeletor transforms himself into his own concept of a god. He is clad in radiant, golden armor and crowned with an opulent, horned head piece, which partially resembles the brief glimpse given of the exterior of the cinematic version of Castle Grayskull. He discharges beams of pure energy from his eyes. During the fight between him and He-Man, his powerfull staff is broken into two, causing Skeletor to lose his god-like powers and as well turning back to normal, but was not through yet with He-Man, as he he pulled out a sword to kill the master of the universe, but is pushed of a watery cliff to his death by He-man's sword. The movie contains a hidden ending, in a post end credits sequence Skeletor resurfaces from the water, with a green skull, surving the fall and announces, "I'll be back". Despite this, a sequel to the movie has never been made.