The evil twin was created by Sidney Ruffleberg on orders from Carltron, with the intent for her to take over Prehistoria. Carltron sent her to the surface some time before the Hero's arrival. The evil twin took command of the Vipers and began to make preparations to conquer the region. In the Volcano she began lowering the pressure of its boiler, causing the Volcano to begin to cool, and also sent the Vipers to the Mammoth Graveyard to gather bones to craft weapons with. The evil twin intended to shut down the Volcano and plunge Prehistoria into an ice age; then, she and the Vipers would be able to conquer the region without interference from Elizabeth and her village.
Elizabeth sent the hero to investigate the Volcano's cooling and he found the twin in the core of the Volcano. Elizabeth appeared to confront her, and the evil twin revealed her plans for the region, then destroyed the path to the boiler to dismiss Elizabeth. The evil summoned her "pet rock," Magmar, to attack the hero, but it was destroyed. With no minions left to keep the hero from stopping her plans, the furious evil twin overloaded the Volcano boiler, causing an eruption.