What are secondary mutations?
A device invented by Grant Morrison in New X-Men. When a mutant is in their 30s, they mutate again and something else happens. This something else rarely has anything to do with the mutant’s original powers. Emma Frost got the ability to turn into living diamond and the Beast turned into a fruity-looking cat creature. None of the post-Morrison writers have brought them up (with the exception of Chuck Austen who tried to say that Magneto’s secondary mutation was that he could never die, but count on that being ignored too).
