"She wears a costume in the comic book," Romijn-Stamos explained, "so I've had these hard-core X-Men fan guys come up to me and say, 'Mystique's supposed have a white dress with a skull belt!' And I say, 'She's a shape-shifter! She can change the very cells of her body! Why would she need clothes?' Then I realize that I'm actually having to defend being naked to a group of guys!"