For Whom The Spell Holds - S2.E9

Zummi finds a section of the Great Book of Gummi that contains advanced magic spells. However, this also signals Zorlok, an evil wizard whom the Great Gummis had imprisoned in a subterranean prison, that he can find the unlocking spell, then be free to inflict violence on all Gummi Bears the world over, then conquer the world. To do this, Zorlok creates a monster to steal the Great Book, causing Zummi, Grammi and Gruffi needing to track it down.