The most bodily altered mutant we've seen in the movie series has been Nightcrawler, who appeared in the second X-Men film. Circus performer Kurt Wagner from Germany, whose appearance can be best summed up as a blue devil, is devoutly religious. Where the filmmakers departed from the comic books was in giving him body art. Seemingly all over his body surface, Nightcrawler has scarified himself, describing the marks as angelic symbols with one etched for each sin he's felt he's committed.Actor Alan Cummings said in interviews that he was shown various sketches and thought the scars designs looked cool, so he gave his approval. It was only then he realized he'd just agreed to make his daily stint in the makeup chair longer by a few hours per day. The scars were achieved by using a syringe to squirt a silicone compound on his skin, making the raised scars, and then Nightcrawler's blue skin tone was applied over both the silicone and his own skin.
X-MEN THE LAST STAND brings variety of new mutants to the screen, and a large number of them wear tattoos however, it's almost like the tattooing was used as an alternative to having to make mutated looking mutants. The tattoos are purposeful marks, worn by human-looking mutants to publicly declare their mutancy, which would otherwise be hidden.
There's a great scene with Ian McKellan as Magneto, which isn't as big or grand as some of his others but which communicates his character and experience exceptionally well. Having spoken out at a mutant meeting, Magneto is confronted by some young mutants.
Quill: You talk pretty tough for a guy in a cape...Pyro: Back off!
Callisto: You're so proud of being a mutant, where's your mark? (Callisto has a large tattoo on her face and a lip piercing, along with other body tattoos showing)
Magneto: I have been marked once, my dear, and let me assure you, no needle shall ever touch my skin again. (pulls up his sleeve to reveal a Nazi concentration camp number tattooed on the inside of his left forearm)
The character of Callisto is one found in the X-Men comic books, however she's been changed a lot for the movie. In the books, she�s lost an eye and has heavy scars on her face. They aren't explained clearly, but are implied to be the result of her attempts to live among humans. The movie Callisto is a very beautiful woman, but the filmmakers have given her a facial tattoo and a labret, which I guess is their way of saying that such practices are ugly. Sadly, I think their decision is weak and doesn't carry the emotional impact that the original character's defacement does.
You can take a look at the tattoos of X-MEN for yourself with the DVD of X-Men - The Last Stand (The Stan Lee Collector's Edition).

