The Marvel Universe is chock-full of teams, from established groups like the Avengers to up-and-comers such as the Champions. A veritable who's who of heroes have served on these teams. Some, like the Vision, are primarily loyal to one team, with the synthezoid spending his superhero career as a member of various Avengers teams. Other heroes are less choosy, flitting between teams, or even being a member of more than one team at once.

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Whether it's the prospect of a new challenge, the thrill of a new costume or that they just can't say no, some of Marvel's heroes seem to be engaged in an ongoing contest over who can join the most teams. CBR has scrutinized Marvel's many teams over the years to pick out 15 examples from this group: those special heroes that just can't let a team recruitment drive pass them by.

15 WOLVERINE

X-men team assignment

In his early years with the X-Men, Wolverine was often portrayed as the ultimate loner -- someone who was uncomfortable as part of a team and preferred his own company. And yet, by the time Logan died in 2014, he was often used as an example of a character that was spread too thin by appearing on multiple teams. So, what changed? The popularity of Wolverine was a key factor, but at first this manifested itself in guest appearances rather than membership of teams outside the X-Men. During the '80s and even into the '90s, Marvel attempted to maximize Wolverine's appearances while still maintaining his established character. This would all change in 2005.

In that year, it's no exaggeration to say that it felt like Wolverine was everywhere, spread across multiple solo titles and team books. When the X-Men line was relaunched after Grant Morrison's departure, Wolverine was a member of the teams featured in "Astonishing X-Men," "Uncanny X-Men" and "New X-Men" (and you thought it was only Spider-Man that had clones). He was also one of the heroes to join Brian Bendis' "New Avengers," giving him a foothold in both the mutant and superhero communities.

14 SHADOWCAT

kitty-pryde-shadowcat

Despite having Wolverine as a mentor for her formative years, Kitty Pryde has the engaging, sunny disposition that makes her a perfect team player. At times she's struck out on her own or tried to leave behind the superhero life, but on each occasion she's been drawn back in. Kitty's original stint on the X-Men ended in tragic fashion, with the team believed killed while she and Nightcrawler were injured. The two would later help form Excalibur, alongside Phoenix, Meggan and Captain Britain.

Kitty's time as part of Excalibur helped her grow in maturity and confidence. The shy young girl that worshiped Alistaire Stuart grew into someone that could tame the infamous Pete Wisdom. After the dissolution of Excalibur, Nightcrawler, Kitty and Colossus found their way back to the X-Men, where Kitty again proved her worth. She was Scott's pick for the "Astonishing X-Men" team and was instrumental in Logan's plan to reopen the X-Men's school. Stepping outside of her comfort zone, she even had a short-lived stint as one of the Guardians of the Galaxy, after she embarked on a relationship with Peter Quill: Starlord. Despite the strangeness of space, and her teammates, Kitty made it look easy.

13 FIRESTAR

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Angelica Jones, the mutant known as Firestar, has been involved with several teams over the course of her costumed career, not all of which have proven successful. Firestar is most well-known for her long membership in the New Warriors and it's easy to see why she enjoyed being in a team with other heroes her age, free from controlling authority figures. Prior to this, her short time as a member of the Hellions, where she came into conflict with the unsavory influence of Emma Frost, had a lasting effect on her.

With her boyfriend, Justice, Angel made the step-up to the Avengers, though it was always clear that this was Vance's dream and that she was only doing it to support him. Despite this, she fit right in. By being more detached from the history of the team, she was able to see her teammates as people, not icons, and proved her worth to the team on multiple occasions. Despite a short-lived retirement from superheroics, Angel later became a member of the teen super-team called The Young Allies. While the team was short-lived, it allowed Angel to strike up a lasting friendship with Greg Willis, aka, Gravity.

12 QUASAR

quasar

Although Wendell Vaughn, the hero known as Quasar, has vast cosmic power, this doesn't mean that he always works alone. Before he gained the Quantum Bands, Wendell was involved with both S.H.I.E.L.D. and Project Pegasus, and he continued to associate with teams and organizations after gaining his great power. Part of the reason is that Wendell's personality has always been that of the average guy who never thought he was better than anyone else. This was displayed when he joined the Avengers and was nervous around those he considered more experienced heroes, despite his immense power.

In the years since, Quasar has been associated with many teams -- both as a full member and as an associate. He was a member of the Star Masters and regularly assisted Nova and the Nova Corps. After his return from the dead, he had a new appreciation for life and his own abilities. This allowed him to assume the leadership of the Annihilators, despite the vast power of its other members, including Gladiator, Silver Surfer and Ronan the Accuser.

11 IRON MAN

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When it comes to teams, it's hard to beat Tony Stark's claim to fame -- he was a founding Avenger, after all, and in the years since has been involved with many incarnations of the team, providing funding, headquarters and technological expertise. Where Tony's record is less flattering is that he has often been his own worst enemy, the consequences of his actions often having ramifications for his Avengers membership. These fall outs have seen him bounce between the Avengers, their West Coast branch, Force Works and "Mighty Avengers" to name but a few, before the tragic events of "Civil War II" brought Tony's heroic career to a seemingly final end.

Somehow, Tony has also found the time for involvement with teams and organizations outwith the Avengers banner. For some years he acted as a weapons designer for S.H.I.E.L.D., while he was one of the heroes that made up the secretive Illuminati group -- a decision that would come back to haunt him in later years. Perhaps the most unexpected team in Tony's history is his recent association with the Guardians of the Galaxy. He joined the team for a short spell in the Brian Bendis run, allowing readers to see a Tony out of his comfort zone yet thrilled by the technological wonders that he was coming across.

10 SPIDER-MAN

Venom Hosts Peter Parker

Like Wolverine, Spider-Man was also a slow starter with teams. In "Amazing Spider-Man" #1 he attempted to join the Fantastic Four, believing that members were paid for their efforts. After their rejection, it would be years until he would join a team as a fully-fledged member. He had countless team-ups, it's true, but his troubled relationship with authority combined with concerns over revealing his secret identity meant that he largely shied away from teams. He joined the Avengers as a reserve member, but it would not be until the launch of "New Avengers" that Spider-Man would become a full-time member. In the years since, Spidey (with the exception of a brief Doc Ock-enforced sabbatical) has been a constant member of the team, even acting as leader.

Spidey's other main team affiliation has been with the Fantastic Four/Future Foundation, helped by his close friendship with Johnny Storm. It was this friendship that led Spidey to full membership of the group, when Johnny requested that he was his replacement in the group in the event of his death. This allowed Spidey to live out his adventurer fantasies and utilize his scientific smarts, with he and Reed Richards making a formidable team.

9 BLACK WIDOW

Black Widow

Natasha Romanov's background as a spy would suggest that she is someone who works better alone and prefers not to get too attached. That was certainly the case when she was first introduced as an Iron Man villain, but in the years since her defection from Russia, she has proven her worth as a valuable member of several teams. Natasha's primary associations over the years have been with S.H.I.E.L.D. and the Avengers. She may have initially joined the Avengers due to her connection with Hawkeye, but over the years has been a member of several versions of the team, including acting as leader during the Bob Harras/Steve Epting run in the mid '90s.

One of Natasha's more unusual team associations was when she joined up with a disparate team of characters -- including Hercules, Ghost Rider, Angel and Iceman -- to form the Champions, serving as the team's leader. Natasha has also had a short-lived association with the Thunderbolts, infiltrating the team in disguise as Yelena Belova (the second Black Widow) in order to gain information for Nick Fury.

8 CAROL DANVERS

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Carol Danvers has been involved with numerous teams during her time as a costumed hero, both on Earth and in the stars. During her time as Ms. Marvel, she was a reserve Avenger. After her powers were stolen by Rogue, she developed a new power-set during a space adventure with the X-Men, leading to her time as a member of the Starjammers. After Carol's new powers faded, she returned to Earth, where she joined the Avengers in Kurt Busiek and George Perez's run. Unfortunately, her tenure was cut short by alcoholism; Carol quit the team rather than admit she had a problem.

In the years since, with her original powers restored, Carol has slowly built up her superhero reputation, both as a solo hero and as a team member. She's been involved with several squads of Avengers, was a member of the all-female A-Force and is currently a member of The Ultimates. The launch of the latest volume of "Captain Marvel," in 2016, also linked Carol with a new version of an old team. She's now the commander of Alpha Flight, Earth's first line of defense against superhero threats, featuring many original members from Canada's national super team.

7 BEAST

X-Men Beast

Fans have long been split over their preferred look for Beast, whether it's humanoid, blue and furry, feline or ape-like. While these arguments can be bitter, there's another Beast topic that's even more polarizing: was he better suited to the Avengers or the X-Men? Strangely, his time as a member of the New Defenders is rarely mentioned in these arguments. While Beast is best known for his time in the mutant corner of the Marvel universe, he joined the Avengers shortly after his transformation into his blue and furry form, remaining with the team for six years. He would follow this up with a long stint as a member of the Defenders, before returning to the mutant world with the formation of X-Factor. For a whole generation of fans, therefore, Beast wasn't seen as an X-Man.

It's easy to see why Beast's tenure with the Avengers is remembered so fondly, particularly when his portrayal is contrasted against his recent time with the X-Men. At times the bouncing, bubbly ball of fur seems to have been replaced with an embittered workaholic for whom fun is an alien concept, including most recently when he was a sort of de facto member of the Uncanny Inhumans. Maybe the Avengers would be willing to trade Rogue for him?

6 JIM HAMMOND

Jim Hammond from Marvel Comics

Compared to Jim Hammond, the other heroes on this list are Johnny-come-latelies when it comes to being team members. As the original Human Torch, Jim has been a team-player since he first joined the All-Winners Squad back in 1946. Many of the same members, including Captain America, Namor and Toro, would also fight alongside Jim in the Invaders. For a long period after this, Jim was not linked to any teams, due to the not inconsiderable inconvenience of being thought dead. Following his return in "West Coast Avengers" he quickly got back to doing what he does best. Since his resurrection he's been involved with the Heroes for Hire, the V-Battalion, a new team of Invaders, the Secret Avengers and S.H.I.E.L.D.

It's easy to see why Jim fits in so well to a team environment, happy to serve as either a leader or team member. From his first appearance, he has had a burning desire to help humanity, while his status as an outsider, always struggling to fit in, means that he's happy to work with a range of allies, from spies to superheroes.

5 U.S. AGENT

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If there's any hero that can rival Wolverine for the "surly loner" award, it's probably John Walker, the hero known as U.S. Agent. Yet, like Wolverine, Walker has come to be linked with several teams, from across the Marvel universe. That's not bad for a guy whose disastrous tenure as Captain America looked set to derail his heroic career before it had properly begun. Walker's first stint as a team member, where he joined the West Coast Avengers and constantly came into conflict with Hawkeye, helped to mellow him somewhat. While he may not have become close friends with many of his teammates, mutual respect was forged and Walker went on to become a member of the team's successor organization, Force Works.

Since the dissolution of the team, Walker's primary stint as an Avenger has been as part of Hank Pym's team of Mighty Avengers, with many of his other appearances coming in other areas. In the aftermath of "Civil War" he was a member of Omega Flight, the Canadian-based superhero team. He also acted for some time as the leader of the Thunderbolts/Dark Avengers, where his strong personality was instrumental in helping keep his teammates in line.

4 BLACK KNIGHT

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Dane Whitman, the Black Knight, is a character that has flitted in and out of the Marvel universe. Perhaps because his power set seems better suited to a Dungeons and Dragons adventure, he has found himself thrown back in time to the Crusades, trapped in the fantastic realm of Weirdworld and fighting with Captain Britain in Camelot. When he has been able to stay in the mainstream Marvel universe, he has typically acted as a team player rather than a solo star. Dane's primary appearances have been in the Avengers, being a core member during Roger Stern's run in the '80s, and then playing a key part in the emotional dynamics of the Bob Harras-era team in the '90s.

Dane has also had spells with Ultraforce after being transported to the Ultraverse, and with the Heroes for Hire and Excalibur. His most successful role in recent years, though, has been as a member of MI-13. As part of this British organization, he found fulfillment and companionship, and even a new partner in the form of Faiza Hussain.

3 ANGEL

Archangel Of The X-Men flying in the sky

The Angel, Warren Worthington, is another character that shows how fans' perception can change depending on when they started reading comics. Since his transformation into Archangel in the pages of "X-Factor," Warren has been almost exclusively linked to the X-Books. Yet, in the period between his X-Men departure and X-Factor return, Warren was active across the wider Marvel universe. He was, along with Iceman, a founding member of the short-lived Champions team, with the two later going on to join the Beast as part of the New Defenders. In both teams Warren was an asset -- not only for his great wealth (The New Defenders residing in one of his properties) but for his skills, powers and experience.

As with Beast, the return to the X-books saw Warren become a more tortured character, struggling with his transformation by Apocalypse into Archangel. As a member of X-Factor, X-Men and X-Force, he has constantly fought against threats to mutant-kind, but also his own internal war against the darkness within.

2 NAMOR

Namor-the-Sub-Mariner

The Prince of Atlantis is one of the most bad-tempered, self-righteous and downright infuriating characters in the Marvel universe. Yet, somehow, he's also been linked with an impressive number of teams. For sheer power alone, it's easy to see why teams would covet Namor. But from his perspective, it appears that -- however much he may try and deny it -- Namor actually enjoys being around his fellow heroes. The pattern was set early when, despite having repeatedly battled the Human Torch, Namor joined with him and other wartime allies to form the All-Winners Squad and The Invaders. He's since been a member of The Defenders, The Avengers, The Illuminati, The Cabal and even the X-Men. Membership of Power Pack surely can't be far behind.

Namor may constantly complain about his teammates -- whether it's the stupidity of the Green Hulk or the boorishness of Hercules -- but it's clear that, on some level, he likes the feeling of belonging. For much of his life, he's been a man searching for what makes him whole, whether that be a family, a Kingdom or a lost people. As part of a team, he can finally be part of something larger.

1 SHE-HULK

Triumphing over stiff competition, the prize for Marvel's greatest team-player goes to Jennifer Walters, the Sensational She Hulk. Unlike her cousin, Bruce Banner, Jennifer is not a loner. Rather, she's the life and soul of the party; someone who thrives on the spotlight and the dynamic of being on a team with other, like-minded individuals. Since she first joined the Fantastic Four as a replacement for Ben Grimm, Jennifer has been linked with a huge array of teams. These include The Avengers, Heroes for Hire, A-Force, The Defenders, The Future Foundation and the Lady Liberators. She even found great success in her personal life as part of the law-firm, Goodman, Lieber, Kurtzberg and Holliway. Her success there only increased when she realized that she had to act as part of a team rather than try and save the day by herself every time.

In many ways, this same lesson has guided Jennifer's whole superhero career. She has the strength, brains and outgoing personality to act as a solo hero, but repeatedly signs up to being part of a team. For Jennifer, super heroics are less fun when there's no-one to share the experience with. Being part of a team allows her to save the day and have good friends at her side while she's doing it. What could be better?

Have we missed out any Marvel heroes who have been on multiple teams? Do you feel that another hero merited the top spot? As always we'd love to hear your thoughts and comments, either on this post or on the Facebook page!