Him is sick and tired of all the villains (including himself) failing in their never-ending plot to destroy the Powerpuff Girls, so he brings the Rowdyruff Boys back to life and stronger than ever.

Princess interrupts a battle between the Powerpuff Girls and the Rowdyruff Boys. She tries to join the Rowdyruff Boys but they reject her, so out of pity the girls let Princess become a Powerpuff Girl.

There's a new Powerpuff Girl in town...or so she would have you think! Her fiendishly foul plot: to trick Santa into turning her into the fourth Powerpuff Girl! (And, in the process, make him believe the Powerpuffs have been very, very naughty!) Now, Bubbles, Blossom, and Buttercup must explode into a Yuletide tornado of bad-girl-thwarting action to put Princess in her place—and keep Christmas from disappearing forever!

When the Professor realizes that all his successful experiments are actually just accidents, he sets out to do something brilliant on purpose!

Buttercup feels left out when she realizes that she doesn't have any special powers like her sisters.