After stealing a tangerine (orange) and watching it split up into different pieces the Amoeba Boys learn how to multiply and make duplicates of themselves.

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!