Callisto was the leader of a group of subterranean mutants known as the Morlocks. She met the X Men after kidnapping the Angel and trying to marry him, loosing his leadership to Storm. She also tried to get Kitty Pryde, with no better luck than the other time. With the destruction of that community in the Mutant Massacre, Callisto sought asylum first with the X-Men and then with Dr. Moira McTaggart. Sent back to New York by McTaggart, Callisto was captured by Masque and transformed into a beautiful woman. She encountered Colossus, who loved her for a while, lost his memory, and the Genoshan rebels. Later, Peter found out his brother Mikhail was still alive, but the man had gone mad, and so did Callisto, after losing her new beauty, joining Mikhail in the collective suicide of the bunch of morlocks who were still alive.

Her main powers were her hypersenses, which she could use to track as well as for poison detection.

Callisto has in the past carried several precision weapons, including a knife and a stingshot.