Craig McCracken Productions

After destroying the city of Townsville in a game of tag, a trio of superpowered little girls must redeem themselves by stopping a vengeful monkey's plot for world domination.

The Powerpuff Girls face their greatest challenge in this 10th anniversary special episode. There exists a Key to the World, which is handed from city to city on an annual basis. Whoever possesses the key rules over the entire world. When the key is delivered to Townsville, every villain in Townsville attempts to retrieve it. When the girls procure it for themselves, they quickly get sucked into a power struggle, fighting the villains and themselves over who gets to rule the world.

When Princess Morebucks finds out that she's been put on Santa's naughty list (in fact, she's the only one on it!), she does a quick re-write, resulting with Bubbles, Blossom, and Buttercup with nothing but coal for Christmas! On top of all that, Princess gets the one thing she wants for the holidays: super powers! Now, the girls have to stop Princess and make sure that Christmas is saved for children everywhere.

Eight-year-old Mac and his imaginary friend Blooregard Q. Kazoo (or "Bloo" for short) often get into fights with his 13-year-old brother Terrence. When Mac's mother tires of this behavior, she tells him that he has outgrown his age to have an imaginary friend and must get rid of him. Crushed by overhearing their argument, except for Terrence, who is rather pleased, Bloo later comes across a TV commercial for "Foster's Home for Imaginary Friends"--"where good ideas are not forgotten," according to the motto.

Wilt is getting tense at Creator Day when Mac keeps mentioning the word "creator" to him. Wilt suddenly leaves in the middle of the night and the Foster's friends look for him.