Wolverine once fought a supervillain named Spore in South America who was composed entirely of cocaine.
2. While undergoing surgery to regain her powers, Jessica Drew (Spider-Woman) was given breast implants. This was a way to explain the stereotypically robust figure Spider-Woman has been drawn within the comics.
3. The very first draft of the ‘Iron Man’ film script revealed that Tony Stark built mechanical tentacles for a scientist in New York, a reference to the ‘Spider-Man’ villain Doctor Octopus.
4. A black Captain America was secretly fighting in WWII at the same time as Steve Rogers. He was one of the few successful results of the US Government’s numerous attempts to re-create the super soldier serum.
5. In the comic event “Fear Itself”, Tony Stark built a suit of Iron Man armor out of the same magical Asgardian metal used to create Thor’s hammer. It is known as the Iron Destroyer Armor.
Deadpool described himself as "Ryan Reynolds crossed with a shar-pei" in a 2004 comic book series, leading Reynolds to believe he was destined for the role.
7. Deadpool’s healing factor is much more powerful than that of Wolverine or the Hulk. While he can survive a nuclear blast, which Wolverine and the Hulk have also done, Deadpool can reattach his head after decapitation, live in the vacuum of space(though he still wears spacesuits to “look cool”), and claims he can survive being thrown into a supernova.
8. Deadpool has "Medium Awareness" which means he is aware that he is a fictional character in a comic book, and is thought to be due to his mental state.
9. 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.
10. While doing a press conference for The Avengers: Age of Ultron, director Joss Whedon admitted that while Agent Coulson is alive in Agents of S.H.I.E.L.D., he still considers the character dead in the movie’s continuity so as to not cheapen his death in the first film.
Hawkeye developed his archery skills working at a traveling circus as a kid.
12. The original ending for ‘Iron Man 3’ featured Trevor Slattery (the false Mandarin) injecting himself with Extremis and exploding doing it incorrectly.
13. Doctor Strange in the Ultimate Universe was killed when the demon Dormammu wrapped his cape around his neck, cutting off his air and causing his head to explode.
14. In “New X-Men #118,” the word “sex” is hidden in the art on every page of the issue.
15. Every day for the first week of shooting ‘The Avengers’, Mark Ruffalo told director Joss Whedon that it wasn’t too late to replace him.
The very first trailer of Sam Raimi’s 2002 ‘Spider-Man’ movie (used to promote the film at various entertainment expos) featured Peter Parker using mechanical web shooters.
17. Deadpool makes a series of 4522 educational trading cards called “Deadpool’s Guide to Super Villains,” which includes pictures, backstories, and fourth-wall-breaking trivia that he provides to new superheroes. This is supplemented by "Deadpool’s Guide to Super Villains Super Accessories,” a series of 1622 appendix cards featuring different villain’s methods of transportation.
18. Despite being over one hundred years old, the ‘X-Men’ villainess Mystique is able to constantly alter and rejuvenate her body’s cells and thereby retain her youthful appearance.
19. In the 1981 ‘Batman Vs. The Incredible Hulk’ crossover comic, despite his relative lack of brute strength, the Dark Knight successfully defeats the Hulk in combat.
20. In the early ‘Thor’ comics, if Thor ever lets go of his Warhammer Mjolnir for more than 60 seconds, he would lose all of his powers and revert to a human.
Due to an artist’s error, Jean Grey appears completely naked in the 245th issue of Uncanny X-Men.
22. The initial origin of Spider-Woman revealed her to be an actual spider that evolved into a super-powered human being.
23. The final issue of ‘The Amazing Spider-Man’, in which Peter Parker is killed and Doctor Octopus takes over his role as the Web-Slinger, proved so controversial that the comic’s writer, Dan Slott, received numerous death threats from angry fans.
24. In early issues of the ‘Ghost Rider’ comic series, Jesus Christ appeared as a supporting character. However, in order to prevent offending religious readers, the character’s storyline was changed by the editorial staff to reveal that he was actually a demon in disguise.
25. After Robert Downey Jr. expressed interest in the role of Tony Stark, Marvel originally told Iron Man director Jon Favreau, “Under no circumstances are we prepared to hire him at any price.” He pestered the filmmakers until they eventually gave him a screen test.