There are 2 main incarnations of the Skeletor character
Masters of the Universe (1987 film)
Frank Langella donned the Skeletor costume in Masters of the Universe. Skeletor was the primary villain in the 1987 live-action film starring Dolph Lundgren, as this was a motion picture, Skeletor was allowed to be far more menacing and less comical. To prepare for the role, Langella had asked his kids questions about the character and watched the series. During the course of the movie, Skeletor captures Castle Grayskull and imprisons the Sorceress. Later he absorbs the power of the Great Eye and transforms into a golden-armored warrior god, but is ultimately defeated by He-Man.
He-Man and the Masters of the Universe (1983)
In this 1980's cartoon series the Skeletor costume is donned by former pupil of Hordak, leader of the Evil Horde. When Hordak and his Horde invaded Eternia and stormed the palace, Hordak broke in and kidnapped one of the King and Queen's twin babies. Man-At-Arms and the Royal Guard captured Hordak's apprentice, Skeletor, and forced him to divulge the whereabouts of his master, who had retreated to his base of operations, Snake Mountain. When cornered, Hordak opened up a random dimensional portal (later revealed to have led to Etheria) and leaped through with the baby Princess Adora still in his possession. Skeletor remained on Eternia, raised an army of powerful minions of his own and took over as ruler of Snake Mountain. Skeletor's main goal is to conquer the mysterious fortress of Castle Grayskull, from which He-Man draws his powers. If he succeeds, Skeletor would be able to conquer not only Eternia, but the whole universe.
