Filmation He-Man and the Masters of the Universe (1983) Edit
In the 1980s cartoon series, Skeletor is a 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 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. At the same time, his other goal is to take revenge on Hordak and overthrow Horde Prime in his bid to conquer the universe.
Skeletor appeared in 71 of the 130 episodes of the 1980s He-Man cartoon (33 episodes in the first season, 38 in the second). While he was occasionally seen as a bumbling figure whose plans were always foiled by He-Man and his friends, his intentions to conquer Eternia were taken seriously by He-Man. He-Man regarded Skeletor as his arch-foe, and Skeletor's plans were sometimes ruined through the fault of his minions rather than by his own incompetence.