He-Man and the Masters of the Universe - Season 2 Episode 10 Trouble in Trolla

Dree Elle comes to Eternia to enlist Orko's help, explaining that an ambitious Trollan wizard called Snoob has defeated Uncle Montork and taken his position as head of the Academy of Magic. Since Montork claims to have felt inexplicably weak when fighting Snoob, they suspect unfair play was used. Orko and Dree Elle go to Trolla, followed by He-Man and Battle Cat, and it soon transpires that Snoob is being controlled by Whiplash, who is trying to learn magic in order to impress Skeletor. It is up to He-Man to stop his scheme, with the help of his Trollan friends!