When it comes to comic book movies, fans love to see the connections run between the franchise. When Tony Stark showed up in the post-credit sequence in The Incredible Hulk, it was a dream come true for comic book fans everywhere. After years of superheroes showing up in their own movies, the world of Marvel was coming together as one cohesive universe. DC Comics followed a few years later when they finally had Batman, Superman and Wonder Woman show up together in the same movie, bringing the Trinity together on the big screen for the first time. While some properties, mainly the X-Men and Fantastic Four worlds, remained closed off from the rest of their Marvel brethren, Spider-Man proved that deals could be worked out to one day connect all the heroes in the Marvel Universe.

However, comic book fans can still make random connections that have nothing to do with the on-screen action, but with the coincidences and connections that come from behind-the-scenes. With so many of the current Marvel actors appearing in other comic book movies in the past and characters on the screen connecting with others in interesting and unexpected ways, there are tons of great connections for Marvel fans to make. Whether it is within the MCU itself, or ways that other comic book properties help connect characters within the cinematic world, here is a look at 15 insane behind-the-scenes connections that tie the MCU together, but that you never knew about.

15 THE MARVEL AND STAR TREK CONNECTION

Disney owns both the Marvel Cinematic Universe as well as the Star Wars movie world. With that said, two key cast members from Marvel movies from the past and present also had significant roles in the Star Trek movie series, bringing two Star Trek starship captains into the roles of Marvel superheroes.

Of course, Patrick Stewart was Captain Jean Luc Picard years before he took on the role of Professor Charles Xavier in the X-Men world. However, a second Star Trek commanding officer only held the role for a short time before dying. Luckily, he was brought into the MCU as Marvel's God of Thunder, Thor. Chris Hemsworth portrayed the father of James Kirk and took control of a starship just long enough to save the entire crew before going down with the ship in J.J. Abrams' Star Trek.

14 ROCKET AND GAMORA'S SORDID PAST

The behind-the-scenes story of the making of Guardians of the Galaxy includes two former flames working together on the movie. Bradley Cooper, who voices Rocket Raccoon is the ex-boyfriend of Gamora actress Zoe Saldana. Not only did the two actors date before working on Guardians of the Galaxy but Saldana actually said in interviews that she had no time for ex-boyfriends. She said that she wasn't interested in having anything to do with some of them -- a quote she made immediately after she broke up with Cooper.

It really makes the connection between Rocket Raccoon and Gamora seem strange when considering who portrays the members of this Marvel superhero team. Whenever Gamora and Rocket have an argument or talk about their relationship in the movies, it is really hard not to remember this connection.

13 BENEDICT CUMBERBATCH BATTLES HIMSELF

There have been many cases of someone playing two different characters in comic book movies. It has happened when someone went from DC Comics to Marvel Comics, such as Ryan Reynolds moving from Green Lantern to Deadpool. It has happened just within Marvel movies, too, with Chris Evans playing both the Human Torch and Captain America. However, when it comes to playing two different characters, Benedict Cumberbatch trumps them all.

Cumberbatch portrays Doctor Strange in the Marvel Cinematic Universe. He was a great fit and delivered a pitch-perfect performance as the Master of Mystic Arts. However, Cumberbatch also portrayed the film's main villain, Dormammu. In fact, he took on both the characters of Strange and Dormammu in the final climactic scene, standing one-on-one with himself!

12 MARVEL LOVE COPIES ITSELF INTO REAL LIFE

This one is known to almost everyone who follows the personal lives of the actors who play the heroes and villains on the big screen. Before he was Batman, Ben Affleck starred as Daredevil. In that same movie, Jennifer Garner took on the role of Elektra, Daredevil's love interest, a love that was not meant to be. In the movie, the two fell in love but they were star-crossed lovers who couldn't make it work in the end.

Of course, in real life, Garner and Affleck also fell in love and ended up getting married and starting a family. Much like the movie characters, this also was not meant to last. Affleck and Garner ended up divorced in a public battle, and Affleck took it one step further when he also divorced Marvel and headed over to DC Comics to play its most famous superhero. As for Garner, her action career died in much the same way her character did in Daredevil.

11 QUICKSILVERS ON INFINITE EARTHS

In 2014, Fox decided it wanted to use Quicksilver, the mutant son of Magneto in their movie X-Men: Days of Future Past. Marvel also decided they wanted to use the character of Quicksilver, one of the early Avengers members, in the movie Avengers: Age of Ultron. The movies started production around the same time and it turned out both studios had the right to use Quicksilver, and both brought the character to life on the big screen.

Marvel signed Aaron Taylor-Johnson to play Quicksilver while Fox signed Evan Peters. This, of course, was an ironic casting coup. Fans remember Taylor-Johnson as Kick-Ass in the adaptation of the Mark Millar comic book, while Peters portrayed his best friend Todd in that movie. Little did these friends know at the time that they would cross over to other comic book worlds as the same superhero.

10 DEADPOOL AND THE BLACK WIDOW

The comic book history between Deadpool and Black Widow got a little interesting back in 2009 when Norman Osborn sent his Thunderbolts on a mission to kill the Merc with a Mouth. At the time, Natasha was disguised as a woman named Yelena Belova in order to infiltrate Osborn's ranks and worked as Black Widow for the criminal mastermind. During the mission, Deadpool and Widow seemed to develop romantic feelings for each other.

That ended when the Thunderbolts killed Deadpool (Thunderbolts #130-131). However, it turned out that Natasha actually saved him by sewing his head back on his body and letting his healing factor bring him back to life, showing that she did care about him. That makes it very interesting when you realize that Scarlet Johansson and Ryan Reynolds were married in real life before the two ended up as the popular Marvel Comics superheroes.

9 AN X-MEN FAMILY AFFAIR

Anna Paquin was one of the key members of the X-Men in the original trilogy, and it was her story arc that tied the movies together. She even returned in X-Men: Days of Future Past and is one of the most important X-Men in the movie franchise outside of Wolverine, Professor X, Magneto and Mystique.

The X-Men have since come to television with both Legion and The Gifted. On the Fox series The Gifted, Reed Strucker is one of the main characters, a human district attorney who helps lock away mutants in camps until he learns his two children are mutants and takes them on the run. Stephen Moyer portrays Strucker and also happens to be Paquin's husband. The two also starred together on True Blood and Paquin has said in interviews that she gave him advice on taking a role in the X-Men universe, but said they will likely never appear together in the franchise.

8 CAPTAIN AMERICA GETS AROUND

Chris Evans has starred in more comic book adaptations than just about anyone in the Marvel Cinematic Universe. Since he got around so much, in just about every possible comic book company imaginable, there is also the fact that Evans shared the screen with many people that joined him later in the MCU.

Evans was the voice of Casey Jones in TMNT, which also featured the voice talents of Patrick Stewart (X-Men). In Push, Evans was a "Mover" named Nick, pursued by bad guys Djimon Hounsou (Guardians of the Galaxy) and Corey Stoll (Ant-Man). In The Losers, Evans was part of a special ops team along with teammates played by Zoe Saldana (Guardians of the Galaxy) and Idris Elba (Thor). In Scott Pilgrim vs. The World, Evans was one of Ramona's evil exes while Brie Larson (Captain Marvel) is Scott's ex-girlfriend. Finally, Evans starred in the post-apocalyptic comic book adaptation Snowpiercer along with Tilda Swinton (Doctor Strange) and Jamie Bell (X-Men: The Last Stand)

7 MICHAEL B. JORDAN PLAYS BOTH SIDES OF THE FENCE

While Chris Evans was the original Human Torch in the first two Fantastic Four movies, it was Michael B. Jordan who took on the role of Johnny Storm in the more recent, more critically bashed adaptation. Now, Jordan returns to the Marvel Cinematic Universe as the villain Killmonger in the new Black Panther movie. That is very ironic when looking at comic book history.

In the comic books, Black Panther at one time took over as a leader of the Fantastic Four when Reed Richards and Sue Storm took time off from the team. That made the Human Torch teammates with T'Challa. On the other hand, Killmonger was one of T'Challa's greatest enemies, making Michael B. Jordan someone who has played two characters sharing very different histories with the Black Panther.

6 X-MEN SLUMMING IT WITH THE PUNISHER

In 2000, Fox started its extremely successful X-Men movie franchise. In that series, Rebecca Romijn-Stamos starred as Mystique, one of Magneto's lead soldiers in his Brotherhood of Evil Mutants. In 2006, the franchise almost died when Brett Ratner took over for X-Men: The Last Stand. In that movie, Ratner introduced one of the comic book series' original X-Men, Angel, played by Ben Foster.

In between those two movies, Lionsgate tried its hand at the Marvel superhero genre by making The Punisher, with Thomas Jane as Frank Castle. In that movie, Castle moves into an apartment building where he meets three outcasts who end up helping him seek vengeance for the death of his family. Two of those outcasts were Joan, played by Romijn, and Spacker Dave, played by Foster.

5 A HUSBAND AND WIFE AI TEAM

It is not unusual for husbands and wives to appear together in movies. However, in the case of Paul Bettany and his wife Jennifer Connelly, the connection is not apparent to anyone who just watches the movies. Most people know that Bettany voiced the AI character of JARVIS in the Iron Man and Avengers movies. Since then, he has become The Vision and the trailers for Avengers: Infinity War give fans their best look at the actual actor behind the voice.

However, the role of his wife Jennifer Connelly was a little harder to recognize. Forget about her original role as Betty Ross in Hulk, because Marvel forgot all about her when they recast the role with Liv Tyler. However, in Spider-Man: Homecoming, it was Connelly who voiced the AI in Spider-Man's high tech suit, Karen. It seems strange that Tony Stark created two AI systems, and they happen to be husband and wife.

4 ANT-MAN ONE-UPPED HAWKEYE

In the Marvel Cinematic Universe movie Captain America: Civil War, two Avengers members joined forces, as Hawkeye and Ant-Man teamed up as part of Cap's team to battle Iron Man in the struggle against the Sokovia Accords. While Hawkeye has been around since Thor, the newer member here was Ant-Man, who had just starred in his own solo movie for Marvel.

However, in real life, it was Paul Rudd who beat out Jeremy Renner in the race to Hollywood. In 1995, Rudd and Renner both tried out for the same movie, and that film would have been both men's first movie role. The movie was Clueless and Rudd won the role as Josh, Cher's ex-stepbrother. While Rudd won that battle, Renner still made his movie debut that same year in National Lampoon's Senior Trip and then beat Rudd to the MCU by four years.

3 JOSH BROLIN'S IDENTITY CRISIS

When Marvel takes over the Fox movie studio, it will have some very important decisions to make. Will the studio reboot the X-Men franchise with all new actors and integrate them into the Marvel Cinematic Universe? Will it let successful movies like Deadpool continue to roll out films? And, looking at that specific franchise, what will Marvel do with Josh Brolin?

This year, Josh Brolin will star in two major Marvel movies -- one for the MCU and one under the Fox banner. On May 4, Brolin will roll into the main MCU and try to conquer Earth as the mad god Thanos in Avengers: Infinity War. Then, two weeks later on May 18, Brolin will appear as Cable in Deadpool 2, one of the most anticipated characters from the X-Men universe. When Marvel takes over, only one can survive.

2 THE MILES MORALES CONNECTION

When fans of the Ultimate Spider-Man watched Spider-Man: Homecoming, there was one Easter egg that made a lot of them smile. When Spider-Man was questioning the guy in the parking garage about Vulture, that man spilled everything he knew and said that he had a nephew named Miles that he wanted to keep safe by keeping those weapons off the streets. Most people figured he was talking about Miles Morales, putting the Ultimate Spider-Man in the same world as Peter Parker.

However, there is an even deeper connection. The actor who played Aaron Davis -- the man questioned by Spider-Man -- was none other than Donald Glover. For fans who pay close attention, Glover was also the voice actor who portrayed Miles Morales in the Ultimate Spider-Man TV cartoon. At the end of the day, a version of Miles Morales has now already appeared in the MCU.

1 IT IS ELEMENTARY

In 2010, the BBC started one of the greatest filmed versions of the Sherlock Holmes saga with Benedict Cumberbatch starring as Holmes and Martin Freeman portraying his man Watson. As most fans know, Cumberbatch is Doctor Strange in the Marvel Cinematic Universe. While it is a smaller role, Freeman plays government official Everett Ross in Captain America: Civil War and in the 2018 MCU release Black Panther. Ironically, they also appeared together in the Hobbit trilogy as Bilbo Baggins and Smaug.

However, it doesn't end there. Robert Downey Jr. also portrayed Sherlock Holmes, his effort coming in the Guy Ritchie movie series that lasted two films. The connection is stronger as Marvel has signed his Watson, Jude Law, to play Mar-Vell in the upcoming Captain Marvel movie. Want a stranger connection? Downey's love interest in his Sherlock Holmes' movie was Rachel McAdams, who also played the love interest for Cumberbatch's character in Doctor Strange.