1. X-Men

While the ‘X-Men’ comic series was originally developed as a simple tale of “Good vs. Evil,” various writers saw potential in the comic’s cast and story to delve into themes regarding the horrors of racism, religious fundamentalism, anti-Semitism, the red scare, the AIDS epidemic, and the struggle of the LGBT community – Source
2. In “New X-Men #118,” the word “sex” is hidden in the art on every page of the issue. – Source
3. 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. – Source
4. Similar to the Deadpool 2 movies, Deadpool in the comics has a sidekick. Bob, an agent of Hydra, joined Hydra for a steady job and dental plan. He has no superpowers or combat training and Deadpool brings him on dangerous missions for his own amusement. – Source
5. After the very first ‘Fantastic Four’ comic was printed in 1961, many fans debated for decades if the Thing’s genitalia had remained the same after he mutated. In 2011, creator Stan Lee finally confirmed that the Thing had a penis made of orange rock. – Source
6. Black Captain America

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. – Source
7. The original ending for ‘Iron Man 3’ featured Trevor Slattery (the false Mandarin) injecting himself with Extremis and exploding doing it incorrectly. – Source
8. 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. – Source
9. 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. – Source
10. 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. – Source
11. Peter’s Web Shooters

Spider-Man invented the web-shooter he uses to swing between buildings and catch criminals. The fluid inside, which forms the webbing, can hold 120 pounds per square millimeter and evaporates within an hour or two. – Source
12. 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. – Source
13. Mark Ruffalo actually discussed playing Bruce Banner with the director of the 2008 film ‘The Incredible Hulk’, but Marvel did not believe he would be right for the role. – Source
14. In “Avengers X-Sanction #4”, the time-traveling mutant Cable notes that Spider-Man is seen in the future as the greatest hero of all-time, even more so than Captain America or Iron Man. – Source
15. 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. – Source
16. Deadpool’s guide

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. – Source
17. 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. – Source
18. After his secret identity as Daredevil was released to the public, Matt Murdock occasionally wore a shirt with the phrase “I’m not Daredevil” printed on it. – Source
19. 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. – Source
20. The initial origin of Spider-Woman revealed her to be an actual spider that evolved into a super-powered human being. – Source
21. Immortal Deadpool

Deadpool is immortal in the comics because Thanos wants to keep him away from Death in the afterlife. – Source
22. Tom Morello, guitarist for the rock band Rage Against the Machine, makes a cameo appearance as the first terrorist guard killed by the title character in ‘Iron Man’. – Source
23. 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. – Source
24. 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. – Source
25. 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. – Source