Mystique is a fictional character from the Marvel Comics universe, primarily known as a member of the X-Men. She is a mutant with the ability to shapeshift, allowing her to change her appearance and mimic the appearance of others. This power makes her a skilled infiltrator and a complex character, often navigating between heroism and villainy. Created by writer Roy Thomas and artist John Byrne, Mystique first appeared in 1978. She is often associated with the Brotherhood of Evil Mutants, a group that opposes the X-Men. Mystique's character explores themes of identity, loyalty, and the struggle for acceptance in a world that fears mutants.