Callisto is a mutant character from Marvel Comics and a sometimes friend/foe of the X-Men. In the comics, she is the leader of a group called the Morlocks: mutants who dwell in the sewers of New York since their bizarre mutations make them too deformed to fit in with human society. Callisto has occasionally come into conflict with the X-Men and has other times helped them fight against villains such as Magneto and Apocalypse.
Callisto is an excellent hand-to-hand combatant and a great tactician. She is familiar with a number of martial arts and frequently uses throwing knives. Her mutant powers include accelerated healing, enhanced strength and agility, and enhanced senses of sight, sound, smell, taste and touch.
X-Men: The Last Stand
In the third installment of the X-Men film franchise, Callisto is portrayed by Dania Ramirez. Her character is somewhat different from her comic counterpart: she is of Hispanic heritage, she does not wear an eyepatch, and her powers include super speed and the ability to sense other mutants and their power types.
Callisto was initially the leader of a group of mutant thugs called the Omegas. She and her gang threw their lot in with Magneto and the Brotherhood of Mutants in order to prevent Worthington Labs from forcefully distributing their cure for the mutant X-gene. With her mutant tracking abilities, Callisto was able to locate several more mutants to bring into the Brotherhood as well as rescue the captured Mystique.
Later in the film, when the Brotherhood attack Alcatraz Island, Callisto battles against the new leader of the X-Men, Storm. Callisto is defeated and killed when Storm throws her into an electrified fence.