Loki, the Red Skull, Ultron—these are some of the most recognizable supervillains in the Marvel Cinematic Universe. They’re villains that you know on sight, if not because of their comic book history, then because their names are plastered all over merchandise. But what about the villains who aren’t household names, the ones who many viewers miss when they go into the theater or flip on the TV?

Plenty of villains in the MCU go unnoticed simply because they either don’t have the same level of fame or don’t get enough screen time. Sometimes they slip under the radar because their TV counterparts differ so much from the source material that they’re barely recognizable even to Marvel’s most avid readers.

Marvel’s TV shows like Agents of S.H.I.E.L.D. and the Netflix shows are excellent places to showcase some of Marvel’s best second-tier villains who would never get a chance to shine in Marvel’s big screen features. While the Avengers and the Guardians of the Galaxy have their hands full with Ultron, Thanos and other big names of the Marvel Universe, Marvel’s heroes on the small screen have their own villains to deal with. So with that said, here’s a list of 16 Marvel Villains You Didn’t Realize Are Already in the MCU.

16. Blackout

Whitney Frost was not the first character in the MCU to control Darkforce. Preceding her was Marcus Daniels (Patrick Brennan), a love-obsessed enhanced person who targeted Agent Coulson’s ex-girlfriend in the Agents of S.H.I.E.L.D.episode, “The Only Light in the Darkness.” Coulson and his team stopped Daniels by blasting him with more light than he could absorb. The overload of energy caused him to explode.

Introduced in Nova #19, Marcus Daniels was the alter ego of the supervillain Blackout. Blackout obtained his Darkforce abilities in a lab accident. Mentally unstable due to the effects of Darkforce on his body, Blackout used his powers to wreak havoc and seek revenge on those he blamed for his condition.

Blackout fell in love with the villain Moonstone who used his affection for her to her advantage. As members of Baron Zemo’s Masters of Evil, Moonstone manipulated Blackout into sealing the Avengers Mansion inside a dome of Darkforce energy. Avengers member Doctor Druid convinced Blackout to resist Moonstone’s control, which saved the Avengers but resulted in Blackout’s death.

15. Batroc the Leaper

Remember that guy played by George St. Pierre who fought Cap in Captain America: Winter Soldier in the first fifteen minutes of the movie? He was a problem for about thirty seconds, right before Cap put his shield down. That was Batroc the Leaper, a French kickboxer from the comics who has been a thorn in Cap’s side since 1966, not because he’s particularly tough to beat, but because he keeps coming back.

Usually recognized for his purple-and-yellow costume and handlebar mustache, Batroc operates as a mercenary, doing almost anything for money. He does have some sense of honor though, and has never done anything outwardly evil. On occasion, he’s been known to turn against his employers to help Captain America, a foe who he respects even more than he hates.

Despite his many losses to Cap (a number too high to count), Batroc is actually an extremely talented fighter, a fact that is often overlooked not just by readers, but by Captain America himself, who called him “a joke” during their first fight. However, Batroc wasn’t offended and has never let his record of defeats keep him down.

14. Angar the Screamer

In a Season 2 episode Agents of S.H.I.E.L.D., Skye’s father recruited a handful of enhanced people to get revenge on Agent Coulson and S.H.I.E.L.D. His secret weapon was David Angar (Jeff Daniel Phillips), a patient at a psychiatric institute who had to wear a mask because of his supercharged vocal chords. His jaw appeared unhinged as he unleashed his sonic scream on the team.

If you’re an avid reader of comic books, this guy may have looked familiar. The sonic scream, the long hair, the last name—they’re all clues that point to a C-list villain that was introduced in Daredevil #100. Angar the Screamer was a radical social activist who volunteered for an experiment.

After developing the ability to emit a powerful sonic scream, Angar used his newfound powers to become a criminal. He also discovered that he could use his voice to induce hallucinations, a trick that he used to get Daredevil and Black Widow to fight each other.

As Angar’s career as a criminal continued, he became involved with Screaming Mimi. The two were partners in crime to the end when Angar was shot during a robbery. It was his death that prompted Screaming Mimi to join the Thunderbolts as the superhero “Songbird.”

13. Lorelei

Introduced in Thor #337, Lorelei was an Asgardian beauty and the younger sister of the Enchantress, a prominent villain of Thor and the Avengers. One thing Lorelei shares with her sister is her unrequited love for Thor. Loki was able to convince her to go with him to Earth so that she could win Thor’s love. She often uses sorcery and love potions to get what she wants. During the times when Lorelei is actually able to enjoy some success in putting the God of Thunder under the spell, it’s up to Thor’s allies to save him.

The version of Lorelei (Elena Satine) that appeared in the Agents of S.H.I.E.L.D episodes “T.A.H.I.T.I” and “Yes Men” was a largely faithful adaption of the character. Not only did she share the same physical characteristics as her comic book counterpart, but she also shared the same effect on men, though this version may have been more powerful. With no Thor around to seduce, she had to settle for Agents Ward and Fitz. Much like the comics, the men under her sway had to be rescued.

12. Korath the Pursuer

At the beginning of Guardians of the Galaxy, Star-Lord was confronted by an alien (Djimon Hounsou) who had no idea who he was, while people watching the movie were probably more clueless about the alien’s identity than Star-Lord’s. The alien in question was Korath the Pursuer, a villain introduced in Quasar #32.

An Agent of the Kree Empire, Korath was a cyber geneticist tasked with developing cybernetic soldiers for the Supreme Intelligence. When he felt that his skills in science weren’t being appreciated, he used his tech on himself, enhancing his physical capabilities.

During the Kree-Shi’ar War, Korath battled the Avengers on the Kree homeworld in what was the first of several meetings. When the Shi’ar won the war, Korath switched his allegiance from the Kree to the Shi’ar. When the Kree eventually took back control of the planet, Korath was treated as a collaborator and severely punished for his crimes against the Empire.

11. Nuke

In the Netflix TV series Jessica Jones, Will Simpson (Wil Traval) was a cop whose determination to kill Killgrave drove him down a dark path. After taking experimental pills, he became mentally unstable and more murderous until he had to be taken down by Jessica and Trish.

Sharing a slightly different name, Frank Simpson first appeared in Daredevil #232 as a villain sent by the Kingpin to kill Daredevil. He was a mentally disturbed ex-soldier with an American flag carved onto his face. After taking part in the Weapon Plus program—the same program that created Captain America’s super soldier serum—Simpson was turned into a partial cyborg.

Psychologically scarred by war and torture, Nuke’s mental issues caused him to become a psychotic killer, putting him at odds with Daredevil, Wolverine and Captain America. Captain America has felt partly responsible for Nuke’s condition, considering that it was the super soldier serum that set the stage for the experiments done to Nuke.

10. Absorbing Man

Crusher Creel was a criminal who received super powers from a magical drink given to him by Loki. As “The Absorbing Man,” Creel’s body could mimic the physical attributes of an object such as wood, iron or even adamantium. Powerful enough to put up a fight against Hulk and Thor, Creel has often been able to challenge entire teams of heroes. For some characters, the only way to beat him is to trick him into absorbing a substance that will weaken him tremendously, like helium or glass. Another handicap is his intelligence, or lack thereof. Creel is a brawler, not a thinker.

Creel’s brutish personality was toned down in Season 2 of Agents of S.H.I.E.L.D. as he (Brian Patrick Wade) appeared to be more of a calculating, efficient enemy under the control of HYDRA. S.H.I.E.L.D. defeated Creel by turning him to stone. Creel returned in Season 3 as a bodyguard to General Talbot. Though initially deemed untrustworthy to S.H.I.E.L.D., Creel proved to be an effective ally.

Though the TV adaption of Creel doesn’t have the comic book character’s personality, his abilities and physical appearance were spot-on. During one encounter with S.H.I.E.L.D. he even got to use his iconic weapon: a ball and chain.

9. Klaw

Avengers: Age of Ultron featured another well-hidden Marvel villain. Arms dealer Ulysses Klaue (Andy Serkis) received a visit from Ultron who wanted to get his hands on a shipment of vibranium. The confrontation cost Klaue his hand.

Comic fans know this unfortunate arms dealer as Klaw, a character found in the pages of The Avengers, Black Panther and Fantastic Four. After murdering Black Panther’s father in Wakanda, Klaw escaped but lost his right hand in the process. After replacing it with a vibranium sound-powered sonic converter, Klaw became an opponent of the Black Panther and the Fantastic Four. He is considered by many to be the greatest of all the villains in Black Panther’s rogues gallery.

Andy Serkis is set to reprise his role in Black Panther. It’s not exactly clear what his connection to Black Panther will be since we already know that his history with the Panther has already been altered from the source material. In Captain America: Civil War, Black Panther’s father was murdered by Baron Zemo, meaning that Klaue will have to commit some other evil deed to invoke the Panther’s wrath.

8. Madame Masque

The main villain in Season 2 of Agent Carter was Whitney Frost (Wynn Everett), a Hollywood actress who gains the ability to control and absorb Darkforce energy. Frost used her money and status to manipulate others, including her husband. She eventually took over the Council of Nine, only to have her plans ruined by Agent Carter.

Though her story differed much from the source material, Season 2 was filled with references to comic book lore relating directly to the comic book version of Frost, “Madame Masque.” One of Frost’s movies was The Nefarious Daughter which refers to Frost’s father Count Nefaria, a villain of the Avengers. Another film starring Frost was The Woman in the Golden Mask, a title that references Frost’s comic book identity.

In the comics, Madame Masque was a villain who had to wear a golden mask to cover up her scarred face. She had no superpowers, but this didn’t stop her from being an enemy of Iron Man. She was a socialite who rose to power as the leader of the criminal organization known as the Maggia. For a while, she tried to reform and fell in love with Tony Stark, but their romance was short-lived. After her father’s death, Madame Masque returned to her villainous ways.

7. Blackwing

Maggia boss Joseph Manfredi (Ken Marino) was Whitney Frost’s old friend and chief ally in Agent Carter. Since he had always been in love with Frost, he used his authority in the Maggia to help Frost accomplish her goals.

Even if you’re aware of the comic book character Manfredi was based on, you’d be forgiven for not recognizing him, since the only connections shared between the two are their name and background in the Maggia.

The comic book version of Joseph Manfredi is the son of Spider-Man villain and head of the Maggia, Silvermane. After developing the ability to control bats (just one of many aspects of his character that was absent from the TV adaption), Manfredi joined Ringmaster’s Circus of Crime as the costumed criminal “Blackwing.” Usually acting as a henchman, Blackwing has worked on the payroll of the Skeleton Crew, HYDRA and Justin Hammer while fighting a number of superheroes including Captain America, Daredevil and the Thunderbolts.

6. Whiplash

No, I’m not talking about the guy from Iron Man 2. I’m talking about Mark Scarlotti, the real Whiplash. The Anton Vanko incarnation of Whiplash is indeed a comic book character, but he wasn’t introduced until a few months before the release of Iron Man 2. Mark Scarlotti is a character whose history goes back to 1968 when he first appeared in the pages of Tales of Suspense #97 as an inventor and assassin for the Maggia. Scarlotti used a hyper-powered whip that was strong enough to slice through Iron Man’s armor.

Iron Man 2 created a completely different version of the character, but where it went wrong, Agents of S.H.I.E.L.D. got it right. In the Season 2 episode, “A Fractured House,” Scarlotti (Falk Hentschel) was introduced as a ruthless mercenary known for almost killing the Avenger Hawkeye.

Scarlotti’s signature weapon was a chain-like whip with a knife at the end. After taking an assignment for HYDRA, Scarlotti was forced into a fight with Agent May, in what was one of the best-choreographed fight scenes of the season.

5. Blizzard

Donnie Gill is the second villain in the Marvel Universe to take the name “Blizzard.” Like the original Blizzard, Gill doesn’t have any real superpowers and has to rely on his suit to generate freezing rays. Blizzard has spent most of his supervillain career battling heroes from all over the Marvel Universe and teaming up with a number of second-tier villains and mercenaries. Blizzard has also served as a member of the Thunderbolts, a group of villains seeking redemption for their past deeds. Unfortunately, Blizzard’s stint as a hero didn’t last, and before long Blizzard was back to robbing banks.

The TV version of Donnie Gill (Dylan Minnette) appeared in the first and second seasons of Agents of S.H.I.E.L.D. as a promising S.H.I.E.L.D. cadet who builds a weather-controlling machine. An accident caused Gill to gain the ability to control ice. Gill used his ice powers to serve HYDRA against his will and is currently believed to be dead.

Since Gill’s appearance on Agents of S.H.I.E.L.D., the comic version of Gill has been revealed to be an Inhuman. With his transformation, Gill has no need for his suit and can control ice at will. The change allows Gill to more closely resemble his TV counterpart.

4. Dr. Faustus

In Season 1 of Agent Carter, Peggy and the Howling Commandos rescued a psychologist named Dr. Ivchenko (Ralph Brown) from a prison cell in Eastern Europe. Dr. Ivchenko presented himself as a mild-mannered doctor with good intentions, but as the season continued Dr. Ivchenko proved to be a murderous hypnotist with a sinister agenda.

In the seventh episode of the season, his real name was revealed to be Dr. Johann Fennhoff, a name shared by the comic book character, Dr. Faustus. Dr. Faustus was a German psychologist who used tricks and pills to break Cap’s will, but Cap discovered his scheme and defeated him. Dr. Faustus wasn’t discouraged however, and has tried numerous times to get his revenge. His history with Captain America has made him a notable member of Cap’s rogues gallery.

Dr. Faustus’s most significant achievement is his role in the death of Captain America. It was discovered that it was he who hypnotized Sharon Carter into helping Crossbones assassinate Cap after his surrender to Iron Man.

3. Graviton

In 1977, the Avengers came to face to face with a villain calling himself Graviton. He had been a scientist named Dr. Franklin Hall who developed the ability to control gravitational fields. He used his power to tear a chunk of ground from the Earth and turn it into a floating island in the sky. The Avengers united to stop him but even with the likes of Thor, Wonder Man, Vision and Iron Man on their side, Graviton seemed too powerful.

Graviton was distracted during the fight when he believed the woman he loved had committed suicide. In his dismay, he caused the island’s destruction. It marked an interesting moment for the Avengers, as it was one of the few times where the heroes didn’t save the day. The villain was done in by his own grief.

Graviton has since returned in other comic book titles, always appearing as a nearly unstoppable villain.

Dr. Franklin Hall (Ian Hart) was introduced in the first season of Agents of S.H.I.E.L.D. as a scientist who discovered a new element called Gravitonium that could affect gravity. Hall was later consumed by the Gravitonium. Though considered dead by S.H.I.E.L.D., Hall still lives within the Gravitonium but has yet to emerge. Considering his history in the comics, that’s probably a good thing.

2. Mr. Hyde

One of the biggest mysteries of Agents of S.H.I.E.L.D. was the identity of Skye’s parents. This question was answered in Season 2 with the introduction of her father (Kyle MacLachlan), a character called “Cal” who is a mentally unstable scientist and a murderer. When Cal meets Skye, he tells her that her real name is Daisy Johnson.

The mention of “Daisy Johnson” is the clue that not only tips off viewers to Skye’s true identity as the superhero Quake, but also points to Cal’s identity: the supervillain Mr. Hyde, a character who has existed in the Marvel Universe since 1963.

Mr. Hyde and Cal share a similar origin: they both developed temporary super strength through a formula they created themselves. A downside of the formula is that it takes a toll on their mind.

What separates Cal from Mr. Hyde is that in Agents of S.H.I.E.L.D. Cal was portrayed as a villain you sometimes find yourself rooting for. Sure, he did some bad things, but in the end all he wanted was to be a family again with his wife and daughter. On the other hand, Mr. Hyde is a sadistic brute whose monstrous appearance is matched only by his personality.

1. Baron Zemo

This is one you may have caught since it was no secret that Baron Zemo (Daniel Brühl) was featured in Captain America: Civil War. After all, he was the man behind the Avengers destroying each other. Zemo wasn’t much of a villain though, and served as more of an instigator than anything else. To any comic fan who doesn’t follow the casting updates, it’s easy to understand why this character’s connection could be overlooked. Brühl’s version of Zemo was not one of the MCU’s best adaptions of a comic book villain by any means.

In the comic books, Zemo is the son of the man known for killing Bucky (an achievement that has since been taken away by the reveal of the Winter Soldier’s true identity). After Captain America was revived, Zemo’s father led the Masters of Evil in an attack on the Avengers, resulting in his death. His son, desperate for revenge, made several attempts over the years to kill Cap. He led a new Masters of Evil in a raid on the Avengers Mansion and succeeded in destroying it.

We probably shouldn’t count on the MCU version of Zemo to live up to the expectations set by his namesake.

Fun Fact: Four of the villains on this list (Baron Zemo, Absorbing Man, Mr. Hyde, and Blackout) all served together in the same Masters of Evil that launched an attack on Avengers Mansion in the 1980s.