Buttercup brings the spice to the Powerpuff Girls. She and her sisters Blossom and Bubbles were all accidentally created by Professor Utonium on the Powerpuff Girls show. Out of all of them, this green crusader loves fighting the most, and has both an uncertain temper (she has been known to challenge Blossom's leadership) and the least tolerance for the softer, "girly" side of life. There has, however, been at least one occasion on which Buttercup has shown herself to be attracted to Ace D. Copular, the leader of the Gangreen Gang.
On the eve of the Fusion invasion of Earth, Buttercup and her sisters were engaged in a fight with Mojo Jojo, who was piloting one of his newest mechs. Buttercup began a rant about how played out Mojo's use of giant robots was becoming, and she and Bubbles continued to belabor the theme in the midst of the battle, much to Blossom's chagrin. With the girls distracted, Mojo seized the opportunity to sneak-attack Blossom with a charge blast; before the impact, however, Buttercup shoved Blossom out of the way and took the blast head on. The blow knocked her senseless and she fell into the ocean, but after her sisters had dealt Mojo an even more than usually brutal defeat, they sought her in vain; she was at last declared missing. Her holographic image now stands in the Heroes Square Monument honoring her along with other heroes who have gone missing.