Episode Title:
Princess Buttercup.
Episode Description:
When Buttercup starts hanging with the Derbytantes, Princess Morbucks wishes to join the Powerpuff Girls. Unfortunately, Princess betrays the girls by giving them a chest that lets out an indestructible "necronium" diamond heart that traps them inside, and it's up to Buttercup and the Derbytantes to save them and stop Princess.
