Even after getting roundly stomped at the box office by the Avengers and other heroes, the X-Men remain Marvel‘s most popular team, characters second only to Spider-Man in wide appeal. And with good reason. Under the guidance of writer Chris Claremont—along with fellow creators such as John Byrne, John Romita Jr., and Louise Simonson—expanded the X-Men from C-list nothings to bestsellers, thanks to their combination of rich drama, high-concept genre trappings, and superhero action.cnx.cmd.push(function() {cnx({playerId: "106e33c0-3911-473c-b599-b1426db57530",}).render("0270c398a82f44f49c23c16122516796");});So important are the X-Men, in fact, that they’re bigger than the X-Men. Marvel has a host of mutant teams and organizations, all the better to appear in other series and maybe even carry their own titles. Some of those are known to casual fans, X-Force, X-Factor, and even Excalibur. But others require a deep dive into the world of Marvel’s Merry Mutants, which we happily supply now.3KOne of the most recent mutant groups on this list, 3K is also one of the more troubling. As their name suggests, 3K looks toward the future, to the year 3000, where mutants will finally rule. Lead by the Chairman, an evil version of Hank McCoy a.k.a. the Beast from the future, 3K counts among its members Xavier’s cruel twin sister Cassandra Nova and Joseph, the clone of Magneto. Together, 3K hopes to spread mutation and completely replace homo sapiens, as seen in the current X-Men and Fantastic Four crossover storyline, DNX.ExilesFor the most part, this list stays within the mainline Marvel Universe of Earth-616. But such rules and designations don’t quite apply to the Exiles, the multiversal hopping team created by Judd Winick and Mike McKone. Led by Blink, a teleporter from a reality conquered by the mutant Apocalypse, the Exiles travel from universe to universe, righting wrongs and visiting worlds not quite like our own. While they do regularly add non-mutants to the line-up, the most notable members tend to be those who carry the X-gene, including a heroic version of Sabretooth, Nightcrawler and the Scarlet Witch’s daughter Nocturne, and the shapeshifter Morph, then only seen in X-Men: The Animated Series.ExternalsA lot of these teams are pretty ’90s. But nothing is more ’90s than the Externals, a convoluted time-travel-adjacent group, that (of course) involves Cable. As you might expect from their name, the Externals all have immortality or long lives as part of their mutant abilities, mutants such as Apocalypse, Gideon, and Selene. The Externals play the long game, and plan to eventually rule over the world… providing nothing goes wrong in the early 20th century. What could go wrong? What is their big plan? None of that was made particularly clear in the plot-heavy stories of the mid-90s. But every time one of the Externals emerged from the shadows to say something cryptic and sinister about Cable, X-Force readers cheered. Fallen AngelsThe X-Men began as students at Xavier’s school, so it makes sense that Marvel would often go back to stories about teen mutants. One of the most interesting examples comes with the Fallen Angels, a spinoff of the primary teen mutant book of the ’80s, New Mutants. After thinking he killed his teammate Cannonball, Sunspot leaves the New Mutants and finds a group of mutant runaways. The original line-up included characters who would go on to become major players, Boom-Boom and Multiple Man, as well as odd-balls such as the cyborg Gomi, who loved nothing more than his pet cybernetic lobsters, Bill and Don. The ragtag nature of the original Fallen Angels meant they didn’t last for long, but another iteration popped up recently on the island of Krakoa.Freedom ForceThe Freedom Force might be the strangest group on this list, precisely because it serves as a transition point between two other mutant teams. Freedom Force began life as the second iteration of the Brotherhood of Evil Mutants, this one led by shapeshifter Mystique instead of Magneto and featuring her wife Destiny, Avalanche, Blob, and Pyro. Mystique made a deal with American official Val Cooper to work as government mutant hunters, taking the name Freedom Force and fighting against the X-Men. Eventually, but not for a long time, Cooper and the government saw the folly of using supervillains to fight their values, and eventually replaced Freedom Force with the far more successful X-Factor.Generation XGeneration X was the third iteration of the teen mutant concept, and one of the most beloved. As its name suggests, Generation X was the ’90s version, who revived the New Mutant’s mission after that group became X-Force. However, this iteration took a decidedly different approach, following not Charles Xavier, but rather Emma Frost, the White Queen, who transformed her posh Massachusetts Academy into a branch of Xavier’s school. There, together with longtime X-Man Banshee, Frost trained the next generation of mutant heroes, including mainstay Jubilee, as well as Chamber, Synch, Cannonball’s sister Husk, and more. The team brought plenty of attitude to help realize Xavier’s dream among the youth. HellionsBefore Generation X, Emma Frost led another team of young mutants, the Injustice Gang to the New Mutant’s Justice League called the Hellions. As interesting as that group was, the most compelling incarnation of the Hellions came much later, during the Krakoa Era, when the new soveriegn nation meant immunity for all mutants. The Hellions brought together some of the most infamous and unique X-Men villains, including Nanny and Orphan-Maker, Greycrow of the original Marauders (more on them in a minute), the Goblin Madelyne Pryor. Led in the field by Kwannon, the Japanese version of Psylocke who had her body stolen by white English woman Betsy Braddock, the Hellions were also headed by Mister Sinister at his most devious. Throw in the Havok, the X-Men’s dumbest himbo, who is there just because he still loves his brother’s ex-wife Maddie, and the Hellions were a delightful bunch of misfits.MaraudersLike the Hellions, the Marauders went from a supervillain team to a more heroic team in the Krakoa Era. However, in this case, the change was more pronounced, since the original Marauders were a hit squad assembled by Mister Sinister (well, assembled by Gambit, for Sinister) to enact the Mutant Massacre. At Krakoa, the Marauders were a group of sailors led by Kitty Pryde to gather mutants and bring them to the nation. Although they had very different lineups and aims, both variations of the Marauders had the same effect, forcing mutants to come together and face the threats built up against them, from outside and within.X-CorpWe’re including the X-Corp here because it’s an interesting idea, even though the concept has never actually been done well, not even in their most recent appearance in season 2 of X-Men ’97. As its name suggests, the X-Corp is a corporation, originally a charitable foundation set-up by Charles Xavier to support those harmed by the destruction of Genosha in Grant Morrison’s run, but eventually more of a business to move wealth toward mutants. Over the years, key members have included Jamie Madrox, the Multiple Man (whose detective agency X-Factor Investigations just barely misses inclusion here), and rich mutants Angel and Monet. As interesting as it is to see how the mutant metaphor intersects with capitalism, none of the various stories have done it justice.XSEFor those who confused X-Corp with X-Corps, Banshee’s paramilitary group, and are disappointed, don’t worry. We’ve got a violent team on this list, in the most ’90s way possible. XSE or Xavier’s Security Enforcers are the X-Men of the future. Specifically, they’re the X-Men of the future from which Bishop and his sister Shard hail. Part military special forces, part police, the XSE does not mess around when it comes to enforcing Xavier’s dream. As exciting as they are, their extreme approach can open them up to some destructive mistakes, including betrayal by Trevor Fitzroy, of the evil mutant rich kids known as the Upstarts.The post X-Tending X-Men: An Introduction to Marvel’s Other Mutant Superteams appeared first on Den of Geek.