The Avengers are nearly synonymous with the term "superhero". With almost 60 years and almost 700 issues, the main Avengers title has cemented itself as an American cultural figure and a keystone of the comic book industry. With such a vast amount of content, the Avengers or one of their associated teams (Secret Avengers, Avengers Unity Division, Young Avengers) have featured a number of Marvel characters over the years --  and some of them weren’t always as heroic as their fellow teammates. Yes, some of them were the very villains the Avengers were formed to combat.

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With wrestling and comic books sharing such a large portion of their fanbases, it comes as no surprise that some of the most widely known and beloved comic book characters have carried out the heel-face turn. Earth’s Mightiest Heroes are no exception. Over the years, the Avengers and their associated teams have welcomed an almost astonishing number of former villains into their ranks. Some of these former villains proved that they have been in it for the long haul, while others reverted back to their old nefarious ways at the first opportunity, and some you might not have known were ever villains in the first place!

15 DEADPOOL

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Despite the character’s recent fame, brought on by his own feature film, Deadpool (aka Wade Wilson) hasn’t always been the mouthy anti-hero fans have come to love. Created by Rob Liefeld and Fabian Nicieza, Deadpool was a flat-out supervillain in his first on-panel appearance in New Mutants #98. However, it was his first ongoing title that turned Deadpool into the pop culture spouting, fourth wall breaking anti-hero that made him a star.

Deadpool survived the shift in comics after the end of the '90s, and has enjoyed a steady rise in popularity, partially due to the wealth of non-canon series' the nature of his character has provided him. Deadpool accepted an invitation to the Avengers Unity Squad from Steve Rogers after the events of “Secret Wars”, solidifying his status as both a hero and an Avenger.

14 BLACK WIDOW

Black Widow (Natasha Romanova) was first introduced to the Marvel Universe by Stan Lee, Don Rico, and Don Heck in Tales of Suspense #52 as a villainess. She first appeared as the corrupting force that colored the start of Hawkeye’s costume career as a villain. However, after her attempts to destroy Iron Man, and eventually the Avengers had fallen flat, Black Widow helped Earth’s Mightiest Heroes take on the racist Sons of the Serpent in Avengers #32.

Unfortunately, Black Widow was forced to decline her initial official invitation to join the heroic Avengers because of a S.H.I.E.L.D mission in Avengers #38. The rest of her costumed career would alternate between working for S.H.I.E.L.D, solo endeavors, and stints as one of the most iconic Avengers of all-time.

13 SCARLET WITCH

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Scarlet Witch (aka Wanda Maximoff) made her debut in X-Men #4 way back in 1964. After a very tumultuous childhood, mostly spent wandering central Europe, Scarlet Witch and her brother, Quicksilver became members of Magneto’s Brotherhood of Evil Mutants. However, thanks to Stan Lee, after leaving the Brotherhood of Evil Mutants, she was added (along with Hawkeye and Quicksilver) to the Avengers iteration known as Cap’s Kooky Quartet.

Though it wasn’t known at the time, Scarlet Witch would become one of Stan Lee and Jack Kirby’s most well-known creations, and would later come to play an enormous role in the Marvel Universe for decades to come. Currently, we’re dealing with an evil Scarlet Witch once more. During the events of “Secret Empire” it was revealed that she has been possessed by the demonic Elder God, Chthon.

12 RED HULK

Red Hulk holding a smoking gun

Before he was the Red Hulk, he was General Thaddeus E. “Thunderbolt” Ross. Ross has been an enemy of the Hulk since the green giant’s creation. Ross’s pursuit of the Hulk (and later, of Bruce Banner) quickly became an obsession. Ross’s obsession with the Hulk overshadowed everything else in his life, including his relationship with his daughter and his military career as it soon led him to illegally (and treasonously) ally himself with the Abomination.

After a string of battles with the original Hulk, and some time spent incarcerated in the Gamma Base, Ross was recruited by Steve Rogers to aid the Avengers in their fight against The Hood. Despite no one knowing his true identity, Red Hulk was finally given membership to the Avengers in Avengers vol. 4 #12.

11 SUNFIRE

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The mutant known as Sunfire (aka Shiro Yoshida) was very reluctant to integrate into the larger Marvel Universe. Created by Roy Thomas and Don Heck, Sunfire’s first appearance (X-Men #64) saw him assuming the mantle for the first time and using his mutant abilities to wage war against the United States government, attacking the capitol. After surrendering to the authorities, Sunfire was extended an invitation to the X-Men by Professor X, which he declined.

Around the time Sunfire and Silver Samurai formed Big Hero 6, it was revealed that Sunfire and his uncle Tomo Yoshida had been involved with Rogue, Blindspot, and Mystique during their tenure with the Brotherhood of Evil Mutants prior to Sunfire’s first on-panel appearance. Later, Sunfire was found drunk on the street by Wolverine, who then extended an invitation for the down-on-his-luck hero to join the Uncanny Avengers.

10 VENOM

Agent Venom

Peter Parker’s one time bully turned decorated army veteran Flash Thompson was revealed as Agent Venom in Amazing Spider-Man #654. After losing both of his legs in Iraq, Flash was given the symbiote by the military so that he could continue going on more high-profile special ops missions. The Venom symbiote had already been bonded to both Eddie Brock and Mac Gargan (aka Scorpion), and with them as hosts (especially the latter), Venom had been solidified in readers’ eyes as a villain.

As the Venom symbiote’s host, Flash put a new spin on the character, painting him exclusively as hero. However as Agent Venom, Flash would go on to join a few teams, most notably the Guardians of the Galaxy and the Secret Avengers, where he enjoyed a few years of uninterrupted heroism before losing the symbiote.

9 MARVEL BOY

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The Kree warrior known as Noh-Varr (created by Grant Morrison and J.G. Jones) initially came to Earth-616 from another dimension, and was promptly incarcerated in the Cube by S.H.I.E.L.D where he declared war on the human race. Noh-Varr played fairly sizeable roles in Marvel events such as “Civil War”, “Secret Invasion”, and “Dark Reign”. During this time, his costumed identity changed a fair amount, from Marvel Boy, to Captain Marvel (with Norman Osborn’s Dark Avengers), and then to Protector.

During Marvel NOW!, Noh-Varr reconnected with the Young Avengers, this time becoming a member of the team, reverting back to his original costumed identity as Marvel Boy. As a Young Avenger, Noh-Varr was strictly a hero. The young Kree meshed well with the team, even dating fellow Young Avenger Hawkeye (aka Kate Bishop) until the end of the series.

8 ROGUE

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Though Rogue has been an important part of the X-Men for decades, it was not where she was introduced into the Marvel Universe. No, her first team affiliation was with the Brotherhood of Evil Mutants. Rogue had been recruited by Mystique, through some very careful conditioning, and proved to be a formidable adversary to the more heroic side of the Marvel Universe.

It was not until the absorption of Carol Danvers’ powers and personality that Rogue saw the error of her ways, and sought refuge with Professor X and the X-Men. Though the other X-Men were opposed to her joining at first, she would eventually go on to lead her own team of X-Men. She would then go on to join Avengers Unity Division after the death of Charles Xavier.

7 SPEEDBALL

Speedball bouncing around the room

Speedball (aka Penance aka Robbie Baldwin) was never a villain, but that didn’t stop the majority of America from believing he was. After the New Warriors engaged Nitro, who created the explosion considered to be the catalyst for “Civil War”, Speedball, along with the rest of the team are presumed blown up and dead. When it becomes clear that Speedball is alive, he is arrested by S.H.I.E.L.D and held responsible for Nitro’s destruction in Stamford, Connecticut.

After his guilt drives him to adopt the moniker “Penance”, Robbie complies with the Superhuman Registration Act and is assigned to the Thunderbolts. Following “Secret Invasion” Penance is persuaded to join Norman Osborn’s Avengers Initiative. After the status quo is returned, Baldwin is seen, as Speedball as a teacher at the Avengers Academy.

6 NAMOR

Never X Namor

Namor the Sub-Mariner was one of the very first Marvel characters (he debuted in Motion Picture Funnies Weekly #1 in 1939)...and he wasn’t a hero. Though Namor’s distrust of surface dwellers led him to join up with Captain America and the Human Torch during WWII after Nazi divers swam too close to Atlantis, he would soon be known for his use of sea monsters against the surface world. While he has always deeply respected Captain America, Namor is a longtime adversary of Cap’s fellow heroes The Fantastic Four.

The Savage Sub-Mariner’s allegiance has been fluid over the years, making it clear that to him, Atlantis comes first.  Despite allying himself with both heroic (The Invaders, the Defenders) and villainous groups (The Brotherhood of Evil Mutants), Prince Namor finally joined Earth’s Mightiest Heroes in Avengers #262

5 SABRETOOTH

Sabretooth fights with the Avengers

Wolverine’s longtime nemesis (first introduced in Iron Fist #14 as a planned member of Iron Fist’s rogue’s gallery), once capable of despicable things, has left a life of villainy behind him. This alignment shift came during the events of “AXIS” where a moral inversion triggered by a failed attempt to give Xavier’s mind control of the Red Skull’s Red Onslaught form. Sabretooth, along with a handful of other villains was recruited as a member of the Astonishing Avengers by Steve Rogers to defeat the morally inverted heroes.

However, while most of the inverted villains returned to their lives of crime, it was later revealed that Sabretooth (created by Chris Claremont and John Byrne) was the only villain whose inversion was permanent. As a result, Sabretooth joined the Avengers Unity Division in order to atone for his past misdeeds.

4 SENTRY

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The Sentry’s role as a villain is...well, it’s complicated. Created by Paul Jenkins and Jae Lee, the Sentry (aka Robert Reynolds) was removed from the memories of everyone in the Marvel Universe as a protective measure against his alternate personality: the Void. The Void is a shadowy being of pure evil, responsible for the death of millions worldwide. While as the Sentry, Robert Reynolds is indeed the Golden Guardian of Good, he is constantly at odds with the Void.

So while the Void is a villainous being, Robert Reynolds is absolved of all wrongdoing on account of a critical weakness: his mental illness. The Sentry suffers from agoraphobia, generalized anxiety disorder, Premorbid Schizotypal Personality Disorder, and paranoid schizophrenia. These ailments are often exploited by his enemies, including the Void.

3 SPIDER-WOMAN

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Spider-Woman’s villainy can be divided into two categories, starting with the time she spent as a brainwashed H.Y.D.R.A operative, then for the time where the Skrull Queen, Veranke, had assumed her identity, facilitating the events of “Secret Invasion”. While neither of these were explicitly her own fault, the guilt she feels from them has compelled Spider-Woman (aka Jessica Drew) for years.

Over the years, Spider-Woman has been a part of several incarnations of the Avengers, both as Jessica Drew and Veranke. Most recently, as Jessica Drew, Spider Woman was a member of the Avengers following the fall of Osborn, and was in their primary field team during “AvX”. Though she has since left the Avengers, she remains a powerful force in the Marvel Universe.

2 SANDMAN

Believe it or not, this longtime member of Spider-Man’s rogues gallery was once a member of the Avengers. Well okay, a reserve member, but still! It all happened after a run-in with The Thing in Marvel Two-In-One #86. The Thing urged Sandman to straighten his life out, and really think about his choices. After his time as Mud-Thing, Sandman didn’t need to be told twice.

Determined to turn over a new leaf, Sandman (aka Flint Marko) joins the Outlaws (a group of reformed Spider-Man villains who aid the web-slinger from time to time). Later, in Avengers #329, Sandman is given a presidential pardon and made a member of the Avengers by none other than Captain America. Though he never served as an active member of the team, he appeared from time to time providing help whenever it was needed before going back to his villainous ways.

1 HAWKEYE

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Marvel’s favorite archer wasn’t always the selfless Avenger we know him as today. Hawkeye (created by writer Stan Lee and artist Don Heck) first appeared in Tales of Suspense #57 back in 1964. This issue of Tales of Suspense would go on to be very important to the Marvel Universe, as it also showed the first date between Tony Stark and Pepper Potts.

Hawkeye’s villainous introduction was an accident -- his attempts to stop a robbery which puts him in the wrong place at the wrong time, and into Black Widow’s arms. This would kickstart a romance between the two that has yet to fizzle. Luckily for us, Hawkeye’s good intentions were quickly made known, and a year later, he would appear as a hero in the Avengers title, eventually alongside Iron Man.

Are there any other Avengers that were evil before they joined the team? Let us know in the comments section!