Since debuting in 1963, the X-Men have been a popular mainstay throughout all of marvel comic books. The parable for civil rights was not lost on fans and no matter the line-up, The X-Men have always stood up for themselves and other oppressed groups. The teams and many of the books’ tagline says it all - “protecting a world that fears and hates them.” Plenty of Marvel’s most mainstream crossover characters are carrying the X-Gene. Mutants like Rogue, Cyclops, Jean Grey, and of course Wolverine have all wandered into Xavier’s School For The Gifted at one point or another.

Professor Charles Xavier hasn’t always been the most altruistic person, let alone teacher - he has more or less always left the door to his school wide open for any and all mutants who ever felt like an outcast to step right right trough. Whether they feel like an outcast or not, some mutants have never been formal members of the X-Men. Plenty have had an affiliation with the school at one point or another, but for whatever the reason, they never donned the X. Here are 10 Popular Mutants Who Were Actually Never Members Of The X-Men (but everyone thinks they were).

10 Squirrel Girl

For some, Squirrel Girl is actually one of the most powerful superheroes in the Marvel universe. She has been able to use her ability to talk to squirrels to defeat all kinds of villains, even the dragon Fin Fang Foom. Initially, she wanted to be a sidekick to her idol, Iron Man. Their chance meeting led her to a career with various Avenger squads, as well as a nanny to Luke Cage and Jessica Jones’ baby.

9 Typhoid Mary

Typhoid Mary never had been part of the X-Men universe until recently joining the Sisterhood Of Mutants. That doesn’t make her any less dangerous.

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Similar to Legion, she has dissociative identity disorder. But her telekinesis and pyrokinesis are always present. Primarily, she has been an enemy of Daredevil, Mary never sought out the wisdom of Xavier, she would wind up working for the Kingpin instead.

8 Franklin Richards

Thanks to his parents’ exposure to radiation and becoming superheroes in their own right, Franklin Richards was born with abilities. The X-Gene usually isn’t revealed until adolescence, but Franklin’s toddler tantrums were enhanced by his reality warping powers. Once a captive of Onslaught, he was able to create a pocket universe and save both the Fantastic Four and the Avengers. Even though he is still a kid, he has been powerful enough to attract the attention of some of Marvel’s cosmic creatures.

7 Quicksilver

Debuting way back in Uncanny X-Men # 4 as one of the X-Men’s villains, Quicksilver would eventually be chosen to join a group of new Avengers. Despite being a Mutant, and his dad Magneto sometimes fighting alongside the X-Men, Marvel’s fastest Mutant has never been a fully-fledged X-Man. No longer a Mutant thanks to his sister depowering most of the Mutant population, Quicksilver was exposed to the Terrigen Mists and now can teleport to the future before bouncing back.

6 Scarlet Witch

Scarlet Witch

Similar to her brother, the Scarlet Witch also debuted as a founding member of the Brotherhood Of Mutants. She also would reform and join the Avengers, not once donning a big X on her person while fighting crime. As a Mutant with reality warping powers, she has also been taught various forms of witchcraft and is a powerful sorceress. Not only did depower the Mutant population, but she and Hope (miming Wanda’s powers) were able to repower the Mutant race when the destroyed the Phoenix Force.

5 Deadpool

The most popular mutant this side of Wolverine has been in and around the entire Marvel Universe since he debuted in 1991. He has been a thorn in the side of X-Force as well as an ally to the team and a full-fledged member of Cyclops’ black-ops X-Force.

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He’s been a running mate of Cable’s and Wolverine’s and even Spider-Man’s verbal sparring partner from time to time. But despite Colossus’ best efforts in the Deadpool movies, the Merc With A Mouth has never been an X-Man.

4 Multiple Man

The strange case of the Mutant who can produce “dupes” of himself. Jamie Madrox, the Multiple Man, not only can produce copies of himself, but all of his dupes think and operate independently of Jamie. They also have the ability to produce clones. This allowed for Jamie to have a son with Siryn (although the Prime Madrox absorbed the baby as a dupe), became an Olympian, a lawyer, and even an Agent Of S.H.I.E.L.D. Oddly enough neither Jamie Prime or any of his clones have ever joined the X-Men.

3 Callisto

There is an entire subset of Mutants that live underground. These are mostly the mutants who looks-wise would never be able to fit in when the rest of society, the Morlocks.

Related: X-Men: The 10 Most Powerful Morlocks, Ranked

The Mutant Callisto is their leader. In one of the more popular Storm storylines, she faces off with Callisto for control of the Morlocks, in order to win her teammates freedom. Storm wins but leaves Callisto in charge as her representative. That is the closest Callisto gets to becoming an X-Man.

2 Quentin Quire

Quentin Quire came to the Xavier School, not only already as one of the most telepaths on the planet; but he was already labeled an all-powerful “Omega level Mutant.” However, the young Mutant has plenty of rebellious thoughts that are counter-intuitive to Xavier’s dream. He started several riots at the school, and even once took Xavier hostage. But despite all of this, it’s better to try and have a Mutant like Quentin under the umbrella of the X-Men, than have him standing against them. While he has been on many adventures with the team and even hosted the Phoenix Force, Kid Omega has yet to be formerly invited to join the team.

1 Manifold

Trained by fellow Australian teleporter, Gateway, Eden Fesi was asked by Nick Fury to join the Secret Warriors. He was immediately thrown into a conflict with the team and had to teleport everyone to safety. After these events and despite being trained one of the X-Associates (Gateway), Manifold has not joined the team and has opted to stay part of the Secret Warriors.

Next: The 10 Best New Mutants Who Graduated To Become X-Men