Buttercup was created along with her sisters in an experiment to create a perfect little girl, whom the Professor hoped to raise with good parenting into an upstanding member of polite society. What he got was 3 little angels with superpowers. He taught them to fight crime and the importance of love, freedom, and sisterhood, being a revolutionarily progressive member back in the Gates of Hades days.

While fighting crime with a passion the girls secretly dreamed of being normal girls, not really wanting all that the Professor wanted for them, wanting to cave to society's pressure to be good little girls who didn't have super powers and leave all the fighting to the men. When the Professor didn't come back after testing his latest secret project, in 1829 the were eventually forced to live at an orphanage despite having scoured the world for their father after King George IV suggested that it would give them character and let them have a chance to see what normal little girls lives were like.

Normal little girls who didn't have a father or other family to take care of them turned out to have pretty horrible lives. The Headmistress of the orphanage frowned on their use of super powers. In 1833 the orphanage burned down and Buttercup was separated from her sisters - they had split up to try and save as many kids as possible (without using their forbidden powers), but one by one had succumbed to the perils of the collapsing orphanage. Buttercup awoke alone and with nowhere else willing to take her in, mostly because of her unladylike attitude, eventually got work at a factory who was more than willing to overlook the strangeness of a child when that strangeness came in the form of being able to do more work on less food and sleep. That was, until her rags got stuck in the gears of one of the giant machines and, instead of getting crushed, ended up destroying the machine and costing the company thousands of pounds. When she was nearing her 11th birthday (1836), Beaten and Bruised, Buttercup was about to give up when a mysterious stranger from the Kerberos Club introduced himself and offered her a place to live.

All she had to do was pass a test. Interested to see once and for all if all the stories about the Powerpuff Girls had been true, she was Challenged to seek out five Villains she fought in the past and defeat them once again. She did so easily, first diving deep into the sea to fight the Monsterous Giant Sea Anemone. This disappointed the members of the Club, since they were not able to see the fight from their observation ship except for a brief moment when she lifted it out of the water to give it a good punch. The second of the villains was the terrible Faerie Prince Joshua Jehosaphat and his Whiteface Minions, people transformed into horrible stretched out creatures with blank white circles where there should be faces. This proved more entertaining as many of the club members were able to witness the battle in faerie lands. Next she took off to the Moon, where she fought the horrible backwaters lycanthrotrope who traveled to the Moon and thus acquired great power known as the Terror of the Moonites, stomping his evil empire once again to the accolades of the Moonite people who once again celebrate the Powerpuff Girls' heroism. The Time Mummy was once again sealed within her Pyramid Time Machine for all time, where her broken spirit would await the judgment of her sleeping peers. Finally, Buttercup tracked down Mary Shelley's Monster, whom she had fought many times before. Despite beating it up she felt sorry for the hideous creature, whom she always thought was cool. Despite apologizing for having to beat him up the Monster refused to talk to her after, but did complain that both Bubbles and Blossom had also beat him up in the last couple years, revealing that they were still alive - but he refused to give any details on their encounters, leaving Buttercup steaming mad.

After this impressive performance she was quickly entered onto the Club's rolls. Buttercup was officially adopted by the man who found her, Lieutenant Colonel Joseph Netterville Burton, who remembered her father and the girls from their old crime-fighting days. But as it turned out he was only interested it to claim the Professors' belongings. Buttercup, having no use for the boxed up remains of the Professors old experiments and lab notes (although they are technically still being held for her until she wants them), was more than happy to be left to herself among people who would more or less accept her and not force her to suppress her super powers; indeed, being encouraged to use them once again to halt the flow of Strangeness across the country. The Professor's financial accounts were put into order for her, and while she does occasionally get the odd bit of assistance from the Lieutenant Colonel, it's not any more than anyone else in the Club.

Buttercup spends her days helping the Club's goals and searching for her lost family. Though she would never suspect that her father still lives after his ill-fated Journey to the Center of the Earth, and her sisters unwilling to reunite into the Powerpuff Girls, that is less a driving ambition as it is simply a desire to see them all again. After all, as she will one day remark, she was named Buttercup because she and her sisters are a Team. An eternal reminder of what they were created to do that she can never escape.