Mystique

Mystique is an amoral mutant shapeshifter and an enemy of the X-Men who appears in Marvel Disk Wars: The Avengers.

Ultimate Spider-Man
Mystique's name can be seen on one of the news tickers, noted being questioned in a string of bank robberies. Spider-Man imagines the musical "Mutant and the Beast" starring Mystique and Beast.

Marvel Disk Wars: The Avengers
She was hired by the Red Skull to steal the DISKs from the Avengers.