Today king of mice, tonight king of dolls. Tomorrow king of everything!
~ The Mouse King
The Mouse King, formerly known as the Mouse Prince, is the main antagonist of the 1990 Canadian animated holiday film The Nutcracker Prince, which is animated by Lacewood Productions. He is one of the few villains who has two forms of his animated version (be it the past and present forms).
When he was still a mouse prince, he along with his mother, the Mouse Queen and the mouse clan stole some blue cheesecake from the queen who planned to make some for her king. The furious king demanded to do something about it, which resulted in Hans and his uncle to capture all the mice. However, only the prince himself along with his mother remained uncaught. In fury, the Mouse Queen with her son headed to Perlipat's chambers and while the prince watched, Perlipat was given the curse.
Later, after a discovery for a cure was found in the Krakatuth Nut, the mice watched as many princes, whom were told not to wear boots due to the spell having to have a man who never wore boots, try and fail. The queen herself was proud as she scolded and abused her son due to the prince not believing her spell will last long. Then, a miracle happened as Hans himself tried and successfully cracked the nut, curing the princess. In rage, the queen sought to use what would be her last spell, cursing Hans and transforming him into a nutcracker. However, during the ruckus, she is killed while the prince himself had his tail crushed. Shocked about his tail permanently bent and his mother gone, he took the crown himself, declaring himself the Mouse King and (after Drosselmeyer with the newly transformed nutcracker were banished) vowed revenge on the Nutcracker himself.
He first makes his appearance after Clara (after she finishes dancing and singing with her doll) when his army appeared and the kitten Pavlova chased after them. However, the king himself scared Pavlova as he made himself known with his army cheering him on. When the Nutcracker awoke himself (along with the other toys), he with his army attacked and just when he looks like he would win, Clara throws her shoe at him, resulting him in getting his cape and tail burned while Clara gets knocked out for the rest of the night.
The next night, the Mouse King arrives back, bitter about what Clara did, even though he gave Clara her slipper back. He rambles on about taking out the Nutcracker in front of her before Clara tricked him into taking chocolates of hers before he gets trapped in the drawer. He gets freed, though Clara refuses to give her nutcracker to him, prompting him to take Pavlova instead. Fortunately for him, she gives in just as the Nutcracker begins waking up and they duel.
Though he seems more victorious, the Mouse King is finally stabbed by the Nutcracker on top of the tree, falling from it and seemingly dead. Later, however, as Clara and the toys with her go to the Land of the Dolls, he awakens, frightening Pavlova. Then, in the Land of the Dolls, the Mouse King, in a psychotic rage, tries to take one last chance of revenge, despite being in critical struggling condition. Finally, just as he is about to finish off Clara, he finally succumbs to his wounds and falls off the top of the balcony with his lifeless body falling into the moat below where he drowns. It is implied that the events are real when Fritz tells Clara about a mouse Pavlova seemingly caught.
I'm king! I am the Mouse King! Haha, I AM THE MOUSE KING! HAHAHAHAHA! You and your stupid spells! (spit) That'll teach you.
~ Prince Mouse self-proclaiming himself King upon his mother's death.
Hey, Nutcracker! Come out and meet your fate, Prince of the Dolls!
~ Mouse King calling the Nutcracker out.
He'll pay for this, cause' I'm the Mouse King, me! And I'm gonna build a mighty army and no-one'll stop me! NO-ONE! And if you think your beloved nephew, Hans is ugly now... HA! Wait till I turn into a pile of splinters!
~ Prince Mouse swearing revenge on the Nutcracker Prince.
In the flashback sequence, the Mouse King looked more like what would it be if Warner Bros animated him, but in the actual story, he looks more like a typical Disney villain due to the actually story's realistic settings. In fact, Warner Bros distributed the movie.