Magneto of the Ultimate Universe has the Ten Mutant Commandments tattooed on his back.
2. Gambit of the X-Men has such respect for Deadpool’s fighting abilities that he once paid him off rather than risk battling him, admitting that fighting Deadpool is tantamount to suicide.
3. Magneto had the number 214782 tattooed on his arm during the Holocaust. Because this couldn’t have been a legitimate Auschwitz number, it was later retconned to 24005.
4. Wolverine once survived for 6 months under a glacier by eating strips of his own arm (with his healing factor growing it back).
5. X-Men #1, published in 1991 is the world's best selling comic book. It has sold nearly 8.2 million copies.
Michael Jackson unsuccessfully lobbied for the role of Professor Xavier in the first 'X-Men' film.
7. A color issue of The Uncanny X-Men that was reprinted in black and white for "Essential X-Men Vol. 2", accidentally revealed Storm's nipple.
8. Stan Lee did not make a cameo appearance in 'X2: X-Men United' or 'X-Men: First Class', despite it being written into his contracts that he appears in any movie based upon Marvel characters he created.
9. In 2010, Marvel offered a special Deadpool variant cover of the comic "Siege #3" to any comic book store that would spend in 50 torn off covers of specific 'Blackest Night' comic books, which were published by their rivals at DC.
10. X-Men: First Class was originally written to be the prequel film for Magneto in the same vein as 'X-Men Origins: Wolverine'. It would have featured Magneto's early years fighting Nazis as a concentration camp prisoner, described by the writer as 'X-Men' meets 'The Pianist'.
Hugh Jackman only agreed to cameo as Wolverine in 'X-Men: First Class' because he got to say, "Go f*ck yourself."
12. Wolverine's first appearance in Marvel Comics was as an antagonist in 'The Incredible Hulk', where he was sent by the Canadian government to kill Bruce Banner.
13. The 'X-Men' comic series was originally considered a second-tier title by Marvel and was even canceled in 1969. The series didn't gain popularity until after it was rebooted in 1976, featuring a mostly new team that included Storm and Wolverine.
14. Deadpool once killed a man just because he believed the Star Wars prequels were better than the original trilogy.
15. According to Sir Patrick Stewart, the new levitating chair that Professor Xavier uses in the film "X-Men: Days of the Future Past" actually worked. It only levitated a few inches off the ground and while Stewart would not reveal how it worked, it's believed magnets were used.
16Magneto and Mystique
Contrary to her depiction in most movies and TV series, Mystique is not Magneto's second-in-command in the 'X-Men' comics and rarely works with him. In fact, she once even leads a team whose specific mission was to arrest Magento.
17. Wolverine's claws were thought to be completely metal until the mid-1990s, when Magneto used his power to yank all of the adamantium out of Wolverine's body, revealing bone claws underneath. He used his bone claws in the comics for 5 years afterward, until adamantium was eventually rebounded to his skeleton.
18. At one point, Mystique was intended to reveal she used her shape-shifting powers to father Nightcrawler with Destiny. However, Marvel didn't think that would be appropriate for children, so Azazel became Nightcrawler's father and Mystique his mother.
19. In Marvel's Earth-616 continuity alone, Jean Grey, a founding member of the X-Men, has died several times.
20. Twilight actor Taylor Lautner was the first actor to be considered to play Beast in X-Men: First Class. However, Lautner's filming schedule was too full for him to take the role.
Nightcrawler, one of the most popular members of Marvel's X-Men, was originally pitched to DC comics, but the character was rejected for being "too weird looking."
22. Rob Liefeld and Fabian Nicieza, both fans of the 'Teen titans' comic series, created Deadpool for "New Mutants #98" while acknowledging his resemblance to the DC villain Deathstroke. They even named him Wade Wilson as an in-joke to Deathstroke's alter ego, Slade Wilson.
23. Director Bryan Singer constantly fought with Storm actress Halle Berry while filming X2. At one point, after shooting had run late, Berry marched off set, telling Singer, "You can watch my black a*s while i walk out of here."
24. The famously immortal and violent anti-hero Deadpool is afraid of cows.
25. As the original 'X-Men' comic series was created in the 1960s, when the civil rights movement was at its peak, Professor X and Magneto were modeled after Martin Luther King Jr. and Malcolm X, respectively.