You'll find these and other awesome facts about X-Men at: imdb.com
1. Halle Berry's role as Storm had to be substantially reduced due to her pregnancy.
2. The script called for Logan to wake up in 1973 in boxer shorts. Hugh Jackman vetoed this in favour of waking nude, saying, "In Australia, if you're next to a really good-looking girl, you're not getting out with boxer shorts on or briefs or anything!"
3. Patrick Stewart and Ian McKellen were performing in a touring production of "Waiting for Godot," when Bryan Singer approached the actors about reprising their respective roles as Professor X and Magneto. According to McKellen, both men were utterly shocked, as they thought they had passed their roles on to James McAvoy and Michael Fassbender, and would never play the characters again. Both Stewart and McKellen were delighted to return to two of their most popular roles, and to work with the younger actors playing the same characters as well.
Including his cameo in X-Men: First Class (2011), this is Hugh
Jackman's seventh portrayal of Logan/Wolverine, which raised his own
record for the most times a comic book character has been played by the
same actor in theatrical films. Jackman is also the only actor to appear
in the entire X-Men film series.