In 2012's The Avengers, the mid-credits scene of the film introduced Thanos to the Marvel Cinematic Universe. The character would make brief subsequent appearances in both Guardians of the Galaxy and Avengers: Age of Ultron and, now, the Mad Titan is set to become the main focus in Avengers: Infinity War. After six years of build up and 10 years of the MCU, Captain America, Iron Man, Thor and the rest of Earth's Mightiest Heroes are banding together to fight an enemy the likes of which they have never seen before. But Thanos isn't the only important comic book villain that appeared throughout the last decade of the MCU.

While certain fans will complain that Marvel's movie villains always end up on the chopping block, the fact of the matter is that there are many comic book supervillains that were introduced in the MCU, whether on television or on the big screen, that are still currently kicking around. We might not know what they have been up to since last we saw them, but they still exist in the wide tapestry of Marvel's live-action universe, ready to pop up again. Here, CBR revisits 10 years of MCU history to list 15 villains fans forget are still lurking around in the universe.

15 ABOMINATION

Abomination from The Incredible Hulk

The Incredible Hulk was the MCU's second movie, and perhaps the most overlooked film of the entire series, considering the change in leading actors. But the film still went a long way to help flesh out the idea of inter-connectivity between Marvel movies. It continued to establish S.H.I.E.L.D.'s presence in the universe, and it also brought in Robert Downey Jr.'s pitch-perfect Tony Stark for a cameo.

But other than establishing the Hulk and General Thunderbolt Ross, the film's villain, Tim Roth's Emil Blonsky, aka the monstrous Abomination, also had a large role to play. The Abomination was defeated by the Hulk in a fight that leveled an entire city block, but the character was left alive. It's believed that Blonsky is still incarcerated, but he could always break out the wreak havoc upon the MCU once more.

14 RED SKULL

red skill in MCU

The Red Skull had a very important part to play in the MCU. Not only did he help create Captain America, but his presence was felt for a very long time thanks to the long, tentacular reach of his villainous organization, Hydra. Although many have assumed that the Skull perished in his final confrontation with Steve Rogers, he actually didn’t.

In the fight, the Skull grabbed the Tesseract and was sucked into the energy consuming vortex that it created, an instance that showed us a glimpse of the cosmos. Since we now know that the Tesseract is the Space Stone and a means of teleportation, it means that the Skull was teleported somewhere else. Where has he been all this time? We don't know, but we would sure like to find out.

13 KURSE

Kurse-Thor-The-Dark-World

Kurse did not have the biggest role to play in Thor: The Dark World, but he was still a formidable opponent for Thor and Loki. Thanks to an enchanted artifact, the wielder of the relic is transformed into a hulking dark elf capable of wiping out all the Asgardians that stand in its way. While many believe The Dark World's Kurse to have perished, he actually could always return.

While Malekith did tell his friend Algrim that he would be the last of the Kursed, the truth of the matter is that more of these enchanted stones could always be found on the home of the Dark Elves. Furthermore, Kurse was defeated by a black hole grenade that sucked him into nothingness. But what if he came out of the other end of this black hole, on the other side of the universe?

12 SCORPION

Certain viewers may not know this, but Spider-Man: Homecoming debuted not only Spider-Man villains the Vulture and the Shocker, but also Mac Gargan's Scorpion. No, we didn't actually see the Scorpion in costume, but the character still appeared. Adrian Toomes meets with Gargan on a ferry to sell him alien equipment – equipment that, we assume, could be retrofitted into a scorpion-like armor.

However, before the purchase can be made, the authorities intervene and Gargan is arrested. We later see the character in prison. It's clear that Gargan has a grudge against Spider-Man now, and the stage seems all but set for Gargan to break out of prison and find the pieces of equipment that were promised to him. Then, fans will finally get to see the Scorpion take on Spider-Man.

11 ZEMO

Helmut Zemo stands apart from most MCU villains because he is one who actually succeeded. By pitting the Avengers against each other, Zemo managed to fracture the team and shake them to their core, a blow that the team will still be reeling from as they head into Avengers: Infinity War. Zemo is a man who lost everything, and his mission to break the Avengers apart was his last goal.

When that was done, he planned to put an end to his life. However, T'Challa was there to stop him, and the villain was later imprisoned. This development might be easy to forget, considering that so many things were happening at the end of Captain America: Civil War – but Zemo is still alive. Worse still, he could once again seek to attack the Avengers, especially if they reunite to fight Thanos.

10 THE COLLECTOR

The Collector explaining the Infinity Stones to the Guardians

There was a time when The Collector appeared to be the next big villain in the MCU, a precursor to Thanos and important player in the hunt for the Infinity Stones. The character first appeared in the mid-credits scene of Thor: The Dark World, shown to be in possession of the Reality Stone. Then, he had a bigger role to play in Guardians of the Galaxy, in a scene that left his collection on Knowhere destroyed.

While the explosion of the Power Stone decimated its surroundings, The Collector was unscathed. We last saw him in the post-credits scene of the film, accepting his loss. However, as an Elder of the Universe and a character who is still in possession of an Infinity Stone, The Collector still might have a part to play in Avengers: Infinity War, even if he isn't an out-and-out villain.

9 THE MANDARIN

A lot of fans were left disappointed by Iron Man 3, a movie that reduced a long-established Marvel villain to a fake, a performance made to distract from the real villain. Aldrich Killian, with dragon tattoos on his torso, declared himself the “real” Mandarin, and many fans were left wondering if he meant that literally. When Killian died, that seemed to be the end of it.

However, fans were so vocal in their disappointment that Marvel would eventually release a short movie titled “All Hail the King,” which revealed that there indeed was a true Mandarin out there who was furious that his identity had been stolen and made fun of. Therefore, the real Mandarin is out there somewhere, and it's just a matter of time before he surfaces – for real this time.

8 JUSTIN HAMMER

Justin Hammer in the MCU

When it comes to Marvel villains, Justin Hammer may not have been the most menacing of threats. Even in the movie he appeared, he wasn't even the main villain, the honor instead falling on Whiplash. However, Hammer was the one who allowed it all to happen, which still manages to make him a mastermind of sorts. Iron Man 2 ended with the villain trying to help in the fight against Whiplash, but he still wound up in prison.

Hammer might be small fish compared to Thanos, but if he ever gets an early release, we could always seem him step up to fill the technological void left by Tony Stark and his company. In fact, Hammer could take a page out of the comics and seek to replace the now defunct S.H.I.E.L.D. with a new, different kind of leadership and equipment under the banner of H.A.M.M.E.R.

7 ABSORBING MAN

Agents of SHIELD Absorbing Man

Carl “Crusher” Creel made his first appearance in Marvel's Agents of S.H.I.E.L.D., but he was also mentioned in the first season of Daredevil quite a few times. However, even then, he hasn't had a very large presence. And yet, Creel is a very big villain in the comics, one who has tangled with many of Marvel's superheroes, from the Incredible Hulk to Black Bolt.

Creel is very powerful, and he could very well be a formidable villain for the movie side of the universe. The character has fought against Phil Coulson and his agents, but his power-levels almost demand him to fight against bigger and more powerful adversaries. Hopefully Creel can make the jump to Daredevil Season 3, or perhaps even get a chance to test his limits against Bruce Banner's Hulk.

6 GLADIATOR

Melvin Potter Gladiator Daredevil

Melvin Potter appeared in both seasons of Daredevil as a superhero tailor. Although he is mentally challenged, the character proved to be a powerful opponent for Daredevil when the two fought against one another. However, it wasn't long before Melvin struck an alliance with Matt Murdock, in order to defend himself from Wilson Fisk. Melvin made Daredevil's suit, his billy club, and even Elektra's costume.

However, the tailor also goes by another name in the comics: Gladiator, a terrifying opponent with round blades for weapons. The series even teased at this development twice already, making it all but clear that Potter and Murdock will find themselves enemies down the line. In the grand scheme of Daredevil and Defenders, it's easy to forget that Potter is around, but he's still out there, waiting to make a suit for himself.

5 GRANDMASTER

Jeff Goldblum Grandmaster

Grandmaster was one of the main villains of Thor: Ragnarok. Though he paled in comparison to Hela, he was still responsible for much of Thor's woes during the first half of the film. As an Elder of the Universe, Grandmaster is not only extremely powerful, he is also the brother of The Collector, whom we haven't seen in the MCU in quite some time.

Before the end of Thor: Ragnarok, the Grandmaster saw his subjects on Sakaar turn on him and his rule. However, the character did not die. In the film's post-credits scene, we see that he is still on Sakaar, and perhaps at the mercy of his people. However, with the power he wields, Grandmaster should have no trouble freeing himself, and perhaps venturing off planet to reunite with his brother.

4 ZODIAC

Marvel Agent Carter Zodiac

In the short movie “Agent Carter” featured on the Iron Man 3 Blu-ray release, Hayley Atwell reprised her role as the strong, female SSR super-agent from Captain America: The First Avenger. The short featured Agent Carter going on a short mission to retrieve a lethal poison dubbed the Zodiac. While Agent Carter was successful in her mission, the origins of the serum were never actually known.

Therefore, it stands to reason that the name given to the poison, “Zodiac,” wasn't for naught. In the comic books, Zodiac is a super-villain group composed of twelve villains, each named after one of the Zodiac signs. It certainly helps that, on the vial of the poison, a symbol that strangely resembles the astrological sign for Mercury can be seen. As far as we're concerned, this is all the confirmation we need to say that Zodiac is out there in the MCU.

3 BATROC

Batroc the Leaper fighting Captain America in Captain America: The Winter Soldier

In the opening sequence of Captain America: The Winter Soldier, Steve Rogers, Natasha Romanoff and the S.T.R.I.K.E. team went on a mission on a freighter to save S.H.I.E.L.D. agents and intel that had been hijacked by Batroc the Leaper. A French mercenary, Batroc gave Captain America a run for his money in the fist fight department, and he even managed to escape.

Last we saw of Batroc, he was in S.H.I.E.L.D. custody, being interrogated. Batroc may not be the biggest Captain America villain in the comics, but he is one that always comes back around every now and then. With the fall of the secret spy organization in the MCU, it stands to reason that Batroc could have easily escaped afterwards. Now, there's nothing stopping him from crossing paths with Steve Rogers again.

2 BARON MORDO

Mordo

Mordo had a large role in Doctor Strange and, much to our surprise, he was an ally of Stephen Strange for the entire film – that is, until the very end. While the movie didn't end with the two as mortal enemies, their difference in opinion saw the allies part ways. Next, we saw Mordo again in the post-credits scene of the film, with a new mission to limit the use of magic in the world.

Now that it has been confirmed that there are no plans yet for a Doctor Strange sequel, we may not see Mordo for a while. But he is still out there, and he is certainly up to no good. Sooner or later, his villainous quest will put him in the crosshairs of Doctor Strange and then, the former allies will have no choice but to realize that they are enemies.

1 A.I.M

Aldrich Killian Guy Pearce

Advance Idea Mechanics joined the MCU in Iron Man 3. The villainous organization was led by Aldrich Killian, and they appeared to have deep pockets and quite a reach. On top of that, they even had super-soldiers in the form of Extremis-enhanced agents. However, ever since the end of Iron Man 3, A.I.M. appears to have died along with Killian.

However, A.I.M. is an important criminal group in the comics, one that is on the same level as Hydra. They don't have a single leader, and they can survive many defeats. This means that the MCU's A.I.M. is more than likely still functioning. Killian may have been their leader, but he wasn't the only head behind it. Sooner or later, A.I.M will return, stronger than ever... hopefully with the yellow beekeeper outfits to boot.