Any good comic book fan should know at this point that a movie version of their favorite story is going to take some liberties. By now, it's disappointment that simply comes with the territory. (Looking at you, 'Watchmen.') Along these lines, purists are raging about 'X-Men: First Class' before it even hits theaters.

And they're not all wrong. The film, a prequel about the young mutants' beginnings in the 1960s, is wildly different from the storylines in the comics. Though it alludes to the earlier films ('X-Men: The Last Stand' and 'X-Men Origins: Wolverine'), it doesn't abide by them. The story is altered enough to make any 'X-Men' fan gasp out loud in the theater. (As this one did!)

Here are five HUGE differences between the comic books and 'X-Men: First Class.'