S1·E5 The Curse of the Spellstone

Skeletor and Evil-Lyn break into the temple of the Fire People and steal the Spellstone, with which they unleash a terrible storm. While He-Man, with Ram Man, Stratos and Battle Cat, goes off to try and retrieve the Spellstone, Evil-Lyn magically disguises herself as an old lady, and convinces Eternia's peasants that the storm was a result of the Elders being angry at the Royal family. She soon convinces them to unleash the Creeping Horac - an ever-growing weed-like entity that covers buildings and gradually sucks away the air - onto the Royal Palace...