The Mouse King, also known as the Rat King in some versions, is the main antagonist in the novel and ballet adaptation The Nutcracker. He is an oppressive ruler who wishes to rule over a magical kingdom where he comes from. He becomes successful as he transformed the prince into a nutcracker and overthrew him. The prince, however, still rebels against the Mouse King, as the story introduces the Mouse King and the Nutcracker Prince waging in a battle against each other, which soon brought the attention of the story's protagonist.