Back when the Avengers finally teamed-up together on the big screen, the response by Marvel fans was overwhelming. But there was one very popular character in the Marvel Universe that fans wanted to see join the Avengers more than any other, but alas it wasn't possible because his movie rights belonged to Sony: Spider-Man. Fast forward a few years, and now Sony and Marvel have reached a deal that allowed Spider-Man to appear in Captain America: Civil War, and star in his own movie, Spider-Man: Homecoming. Thanks to this deal, we finally got to see Spider-Man team-up with Iron Man and fight Captain America. But why stop there?

RELATED: 15 MCU Roles That Absolutely Need To Be Recast

After the massive success of Spider-Man's introduction in the Marvel Cinematic Universe, we here at CBR have turned our eyes to Fox, the movie studio that owns the movie rights to the Fantastic Four and the X-Men. We don't know the future, and we certainly don't know what discussions take place between executive producers, but what if Marvel and Fox reached the same type of deal, one that allowed Marvel Studios, just like Spider-Man, to re-cast these roles for the MCU? That is why, today, we'll take a look at 15 Fox-owned characters we'd like to see team-up with our favorite Avengers!

15 SPIDER-MAN AND JOHNNY STORM

Spider-Man-and-Johnny-Storm

Spider-Man and Tony Stark had a great mentor-mentored, almost father-and-son type relationship, and while we would like to see more of that going forward, there are many more comic book characters that Peter Parker has a history with in the comics that we would love to see. First among them would be the Fantastic Four's Johnny Storm, and the friendship the two share.

In the comics, Peter and Johnny are best friends and were even roommates at one point. In fact, the Human Torch is actually considered part of Spider-Man's supporting cast. For that reason, were a deal made between Marvel and Fox, we could finally see a new actor roughly the same age as Peter cast in the role of Johnny Storm to interact with Tom Holland and bring to life one of the most epic friendships and fiery team-ups in comics.

14 THE SILVER SURFER AND THE GUARDIANS OF THE GALAXY

Silver Surfer flies his board through the stars in Marvel Comics

The Guardians of the Galaxy have a long history of travelling through space and encountering many different races and threats, so it would only make sense for them to eventually come into contact with the being known as the Silver Surfer, a powerful entity who roams the spaceways on his surfboard. Such an outlandish character would be right at home in the tone and universe of James Gunn's Guardians of the Galaxy movies.

In the comic books, massive cosmic threats led to the Silver Surfer and various members of the Guardians of the Galaxy joining forces. Such an event would be easy to imagine taking place in a new Guardians movie, and the Silver Surfer would be another powerful ally for Peter Quill, Drax and Gamora to befriend, antagonize and make fun of, all at the same time.

13 ROGUE VS MS. MARVEL

Rogue-Miss-Marvel-fight

The Captain Marvel movie may still be a few short years away, but that hasn't stopped us from thinking about what could happen in the film. While most people are familiar with the X-Men's very own Rogue, they might not know the source of her powers. No, we're not talking about her mutant ability to absorb the powers of others, but rather her ability to fly and have super-strength, as seen by most in the X-Men: The Animated Series.

In the comic books, that was the result of Rogue permanently absorbing the powers of Carol Danvers, aka Ms. Marvel, aka Captain Marvel. If Fox were to allow Marvel to use their mutant characters, then perhaps we could finally see these two characters throw down on the big screen, a gasp-worthy battle between two powerful female characters that would result in a comics-accurate Rogue.

12 GALACTUS VS THE WORLD

Galactus

Other than the fact that the third Avengers movie will be titled Infinity War and will pit Earth's Mightiest Heroes against Thanos, we don't know much about the future of the MCU as whole. The fourth Avengers movie is still untitled, and after that, who knows what the next big threat will be? Well, how about a celestial being as old as time itself, a devourer of worlds in a purple hat?

Heralded by the Silver Surfer, Galactus could come from the other side of the Universe and find his way to Earth, threatening all life upon it. This massive, gigantic threat would once again require the attention of every hero of the world, and of worlds beyond. No matter which characters would be introduced in Marvel's next movies, they would all have to take part in this massive fight to save the planet.

11 BLACK PANTHER AND STORM

Storm-and-Black-Panther-marriage

Black Panther's solo movie is coming very soon, and from our look at the first teaser trailer, it already promises to be something very special -- the story of a good man, trying to be a King. But there comes a time when a King, any King, needs a Queen. For those who may not know, the X-Man Storm became T'Challah's wife and Queen of Wakanda in the comic books.

For a time, Storm was the woman at T'Challah's side, equal parts strong, supportive and yet defiant. Were Fox and Marvel able to share their characters, we could finally see a comic book-accurate Storm find her way to Wakanda and we could witness an epic and royal love story that would undoubtedly be doomed from the start, just like in the comic books.

10 STAR-LORD AND KITTY PRYDE

Star-Lord-and-Kitty-Pryde

While this might sound like a very off pairing, Star-Lord and Kitty Pryde started a very quirky yet endearing love story in the far reaches of space. One of them Earthbound, the other out in the stars, this made for the most extreme of long-distance relationships, but it never stopped both characters from spending time with their other half.

Seeing as how Star-Lord is currently in a bit of a will they/won't they relationship with Gamora in the Guardians of the Galaxy movies, the arrival of a new actress among the movie's cast could bring a love triangle to the story. With Peter Quill and Kitty developing a bond, it would be interesting and equally hilarious to see Gamora develop feelings of jealousy, and how she'd deal with it. We're guessing a sword would be involved.

9 SCARLET WITCH AND HAVOK

Scarlet-Witch-and-Havok

As an X-Man with his fair share of fans, Alex Summers is more than due for his rightful spotlight. An appearance in the MCU could finally get him his proper due, and it would be novel to see him team-up with the Scarlet Witch, Wanda Maximoff. While the both of them are mutants in the comics, it would be interesting to see this new, non-mutant version of Wanda react to someone with powers like herself.

Besides, as the youngest member of Captain America's Avengers, Wanda doesn't have many fellow teammates that share her age. Alex could be around her own age and he could act as a surrogate brother, after the tragic loss of Pietro. Alex could even be in need of help in controlling his powers, just like Wanda was -- someone she could teach. And besides, they could start a whole new team together... But more on that later.

8 DEADPOOL VS. HAWKEYE

Hawkeye-vs-Deadpool

Hawkeye and Deadpool might not be the two characters you'd expect the most to team-up, but the comic book miniseries Hawkeye vs. Deadpool by writer Gerry Duggan is a perfect example of how well these two can work together. With each subsequent movie appearance, Jeremy Renner has given us more and more of the snarky Clint Barton, so the next logical step would be to pit him against Wade Wilson.

Now, while most Fox roles would have to be recast similar to Spider-Man's Tom Holland for this new interpretation, there would be absolutely no reason to recast Deadpool. Ryan Reynolds has already proven that he is the perfect Deadpool, and with his movie semi-taking place in the MCU (is that a Hellicarrier?), we have no doubt that he and Renner would light up the screen as they trade quips, blows and arrows.

7 BEAST AND BLACK WIDOW

Beast-and-Black-Widow

For a time, Captain America had formed a black ops-like team of Avengers, a group aptly named the Secret Avengers, to take on darker and quieter threats that the regular Avengers were otherwise too occupied to deal with. They were effectively a spy unit, operating in the shadows, unseen and unheard of... if the mission went according to plan.

Among the members of that team were Hank McCoy, aka Beast, and Natasha Romanoff, aka Black Widow. Now, Black Widow already has some history dealing with men with a beastly side in the MCU, so these two teaming up for some spy missions under Captain America's orders could be a nice way to send Natasha back to her spy roots. Besides, we could have a perfect, blue-furred portrayal of Beast appear on-screen all at the same time. Win-win.

6 CAPTAIN AMERICA AND CYCLOPS

Captain America shields himself from Cyclops's optic blast in Marvel Comics

As the leader of the Avengers, Captain America has become one of the most important and beloved characters of the MCU and its fans. But while Cyclops is a popular character in the X-Men comic books, the movies have failed to portray him accurately as the battle-hardened leader he is supposed to be. But his arrival in the MCU could change all that.

As leaders of their respective teams, Captain America and Cyclops could easily come to blows as they have in the comics before. Whoever Marvel would cast as Scott Summers would have to be able to hold his own against Chris Evans, of course. Then, their meeting, fight and eventual team-up could end up being something that fans of both the X-Men and Avengers have waited for for a very long time.

5 IRON MAN AND DOCTOR DOOM

Iron-Man-vs-Doctor-Doom

Tony Stark and Victor Von Doom have quite the history together in the comic books. They've faced off countless times, they've traveled back to medieval times together, and now Doctor Doom has taken a missing Tony Stark's place as the Infamous Iron Man, trying on a hero's life for size. A team-up between the two of these larger than life characters is one that any Marvel comics fan would love to see.

From a battle of armors red and gold versus green and grey, to the classic clash of science versus magic, there would be a lot of spectacle to be had in a confrontation between Iron Man and Doctor Doom. A rivalry that stretches back decades could be introduced in the MCU, and this could allow for someone to try and take up the mantle of Iron Man after Robert Downey Jr. retires from his most famous role.

4 SECRET INVASION

secret-invasion

A few years go, a massive event called Secret Invasion took over the entire Marvel comics universe. It told the story of an invasion of the shape-shifting alien race known as the Skrulls, a race with strong ties to the Fantastic Four and whose film rights currently reside with Fox. Should Marvel Studios finally be able to use these classic aliens, they could finally adapt this captivating story to the screen.

Starting out as a secret infiltration of the Avengers, this invasion quickly became a question about trust, when no one in the Marvel universe could be certain who was a shape-shifting Skrull, and who wasn't. The event involved every major superhero of the Marvel Universe taking the fight to the Skrulls, and it could be used as a template for the next big story in the MCU going into phase four of their plans.

3 HULK VS THE THING

In the comic books, Bruce “The Hulk” Banner and Ben “The Thing” Grimm have thrown down quite a few times. That's no wonder, considering both are super-strong and can easily hold their own against the other. As the strongest member of the Avengers, the Hulk has quite an opponent on his hands when he faces the Thing, and the ensuing brawl would be a cinematic rumble for the ages.

Every fan has wondered who the strongest truly is between these two, and a team-up on the big screen could finally give us a definitive answer. An MCU-appearance from the Thing would light up the screen and not only would him facing off against the Hulk be something that any Marvel fan would love to see, it's a team-up that could become a classic pairing, just as it has in the comics before.

2 UNCANNY AVENGERS

Uncanny Avengers

After the devastating events of the Avengers vs X-Men comic book storyline, Captain America created a new team of both Avengers and X-Men to unify these two separate teams. Assembled, they formed the Avengers Unity Squad, and counted among its members characters like Thor, Captain America, Scarlet Witch, Havok, Rogue and Wolverine.

Such a team would be perfect for the big screen. With a new cast chosen to embody the X-Men, we could have the perfect team-up between both Avengers and X-Men. A new Wolverine, a new Rogue and a new Havok could join forces with Captain America and Thor to take on the forces of a powerful and resurgent Red Skull with the powers of Charles Xavier, just like they had in the comics. Avengers and X-Men, side-by-side: who wouldn't want to see that?

1 THE ILLUMINATI

Evil-Heroes-Illuminati

Tony Stark. Stephen Strange. Mister Fantastic. Professor X. Together, all of these characters had formed a secret cabal known as the Illuminati, a group of the world's most powerful and influential superheroes in their respective fields that would discuss the current goings-on of the Marvel universe and shape them as they saw fit.

Were Fox and Marvel Studios able to share their characters, we could finally see Charles Xavier and Reed Richards meet up with Doctor Strange and Iron Man to discuss the current state of the world and how they could save it. A meeting of such minds would be a different kind of explosive experience, and if Marvel were to see it fit to also add King Black Bolt and Black Panther to this group, we could finally and truly have a unified MCU, from the small screen, to the silver one.

Which Fox and Marvel characters would you most like to see interact? Be sure to let us know in the comments!