With Disney's acquisition of Fox, many comic book movie fans are now eagerly anticipating certain Marvel characters joining the MCU -- perhaps most notably, the X-Men. But while it will be exciting to see how the MCU brings its mutant heroes to life, some fans are lamenting the end of the X-Men's own cinematic universe.

Going back to 2000's X-Men, the franchise helped kick-start the superhero movie genre. Since then, the franchise has played around with different timelines, spun-off into new films and brought beloved characters to the big screen. It also featured a stellar cast over the years. However, as with most franchises, there are a number of famous faces who narrowly missed joining the films. Look back on what might have been with some of the actors who were almost cast in the X-Men films.

RELATED: All The X-Men Movies In Chronological Order

Sigourney Weaver - Emma Frost

Bryan Singer may be losing all his directing jobs these days, but there was a time that he was a very in-demand filmmaker. After helming the first two X-Men films he was getting ready to prep the third which would tackle the popular Dark Phoenix storyline. However, Singer left the film to make Superman Returns and X-Men: Last Stand ended up falling short of the epic conclusion that was promised.

Part of what fans missed out on with Singer's original idea was the inclusion of Emma Frost, a powerful mutant from the comics. Even more exciting, they were pursuing Sigourney Weaver for the role. It's a real shame that version never came to fruition.

Kevin Nash - Sabretooth

Tarzan raising his fist in Magic Mike.

Sabretooth is a popular villain and primary antagonist of Wolverine in the comic books. He is always a massive beast of an individual, so the movies had a tall task trying to find a suitable actor for the live action role. It's not surprising, then, that they turned to the world of wrestling to fill the part.

Tyler Mane was eventually the man who got the job, but fellow wrestler and actor Kevin Nash (The Punisher, Magic Mike) was also considered. Mane himself confirms his competition for the role but suggests Nash was a bit out of shape at the time.

Ethan Embry - Nightcrawler

Ethan Embry and Jennifer Love Hewitt in Can't Hardly Wait.

X2: X-Men United is considered one of the best of the X-Men films and the movie's highlight is the inclusion of Nightcrawler. The mutant with teleportation abilities gave us an amazing opening action scene when he attacks the White House.

As fun as the role was in the film, it required an actor to go through a whole lot of prosthetic makeup to look the part. One actor that seemed undeterred by the process was Ethan Embry (Can't Hardly Wait, That Thing You Do). While Embry did discuss the part with the filmmakers, Alan Cumming was eventually cast.

Rachael Leigh Cook - Rogue

Rachael Leigh Cook in She's All That

Comic book fans noticed that the film's version of Rogue differed quite a bit from the source material. However, the role was a substantial one in the 2000 film which was played by Oscar-winning actress Anna Paquin. However, it was apparently another young actress that was first offered the role.

RELATED: Marvel Finally Explains The Secret Of Rogue's Power

Rachel Leigh Cook (She's All That) was given the role but turned it down. Coming from the indie film world, Cook was put off by the long production schedule as well as having doubts about the budget. To be fair, this was long before superhero movies were a sure-thing.

David Harbour - Blob

David Harbour as Hopper in Stranger Things

David Harbour is becoming quite a popular face in comic book films. He'll be taking over the role of Hellboy in the upcoming reboot and he's just been cast in the Black Widow solo film. But years ago, he almost had his first superhero role in an X-Men film.

Harbour auditioned for the role of Blob in X-Men Origins: Wolverine. Harbour hilariously tried to show off his impressive gut to the filmmakers, thinking it appropriate for the part. But the move backfired as they decided Harbour might be too out of shape for the part.

Josh Holloway - Gambit

Gambit has been a fan-favorite X-Men character for years. There have been hopes of seeing him on the big screen for years. But to date all we've had was Taylor Kitsch's brief part in the lackluster X-Men Origins: Wolverine and the long-promised but never delivered Gambit solo film with Channing Tatum.

Fans almost had a chance to see the Cajun bad boy in X-Men: The Last Stand with Lost star Josh Holloway in the role. Holloway was told he had the part before the filmmakers decided to make the character younger, then ultimately cutting his appearance altogether.

Jim Caviezel - Cyclops

Jim Caviezel in Person of Interest Season 5 Episode 12

Most fans would agree that Cyclops is a character that was never done properly in the films. In the comics, he is usually seen as the leader of the mutant heroes, but the films have him playing second fiddle to Wolverine or getting totally sidelined.

RELATED: 11 Times Cyclops Was A Total Jerk

James Mardsen did a good job in the first three films, but without much to work with. Another actor who was almost stuck with the thankless role was Jim Caviezel (The Passion of the Christ). Caviezel claims he was actually cast but ultimately had to pull out due to scheduling conflicts with his film Frequency.

Brad Pitt - Cable

John Smith smiling in Mr. & Mrs. Smith

Deadpool was a breath of fresh air in the superhero genre. The Merc with a Mouth is a beloved character and his irreverent and dirty humor was unlike any of the other X-Men films. The first film ended with the enticing promise of Cable joining the sequel.

While Ryan Reynolds seemed made for the role of Deadpool, many actors were considered for Cable. One of the biggest names linked to the part was Brad Pitt. Pitt met with the filmmakers and seemed keen on the part but couldn't fit it into his schedule. He did, however, have a hilarious cameo in Deadpool 2.

Angela Bassett - Storm

American Horror Story Freak Show Angela Bassett

With such a big franchise as X-Men, it would seem like the filmmakers could get their top picks for all the roles. But when it came to the pivotal role of Storm in the original film, they were sadly turned down.

Angela Bassett seemed like perfect casting for the weather-controlling mutant. Unfortunately, Bassett seemed to know how ideal the casting was and asked for a salary that was beyond what the film could manage. While Bassett no doubt would have been amazing in the part, she later joined the MCU in Black Panther.

Russell Crowe - Wolverine

Russell Crowe in Gladiator

As iconic as certain roles might be, sometimes actors have good reasons for turning down these parts. Things like scheduling conflicts or dissatisfaction with the script are all legitimate excuses. Russell Crowe's reasoning for turning down the role of Wolverine is a bit stranger.

Crowe having just finished Gladiator, in which his character had a pet wolf, was afraid he would be typecast with another wolf role. The problem with that reasoning is that wolves and wolverines are completely different animals. Odd excuse aside, Crowe still made a significant contribution to the franchise by recommending fellow Australian Hugh Jackman for the role.

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