In the Marvel Universe, mutants are those who are gifted, born with special powers and abilities created by inhabitation of the X-gene. They’re generally considered to be the next evolution of homo sapiens, sometimes being called homo superior. The word was first used in Amazing Detective Cases #11 in 1952 where The Weird Woman describes herself as a mutant. However, the term was used sparingly through the ’50s until comic legend Stan Lee brought the idea to the mainstream. Not wanting to create different origin stories for several characters, Lee popularized mutants in the early ‘60s with first X-Men comic in 1963. Lee thought the adolescent mutants who were discovering their powers should still go to school so he created Professor X’s School for Gifted Youngsters. Since mutants were typically seen as outsiders -- and sometimes dangerous -- by normal humans, Professor X’s school mutants a place to be around others like them while learning how to summon and control their powers.

Since many of our favorite heroes and villains have special abilities like super strength, accelerated healing power, or extraordinary speed, we sometimes forget that these characteristics are often acquired rather than natural. For instance, Spider-Man has spider senses, web shooters, and amazing agility, but he’s actually Peter Parker, a kid who got those powers from a radioactive spider bite. Let’s take a look at some our favorite characters we sometimes forget aren’t actually mutants since they weren’t born with their abilities. For this list, we stuck to the Marvel comics since it tends to use the word “mutant” the most.

20 IRON MAN

Iron Man’s journey began in the early ‘60s when comic legend Stan Lee came up with the idea of creating a different kind of superhero. As the son of a wealthy businessman, Tony Stark was a boy genius and eventually inherits his father’s company after he loses his life in a car accident.

As a human, Stark doesn’t have any superhuman powers. He created the Iron Man suit with a fellow prisoner after being captured by Wong-Chu. From there, Stark has continued to improve his suit for speed, strength, and efficiency. Although he wears a magnetic chest piece that prevents shrapnel from reaching his heart, Stark is not a mutant and he often battles very human problems such as alcoholism and loneliness.

19 THOR

Derived from German mythology, Thor is the Asgardian God of Thunder and son of Odin. Seeing that Thor needed to be taught to be more humble, Odin gave him a human body and placed him on Earth as a medical student named Don Blake. Once Blake finds his magic hammer Mjolnir, he transforms back into Thor but must continue to lead a double life.

As a doctor, Thor meets Jane Foster and falls in love. She serves as one of his motives to protect Earth from evil, even refusing to return to Asgard at Odin’s request. With an almost immortal body and power to withstand punishing blows, it’s easy to think that Thor could be mutant, but he is indeed a God.

18 LOKI

As Thor’s brother, and also son of Odin, it makes sense that Loki is not a mutant either. His enhanced strength, stamina, and speed abilities come from the fact that he is of the Frost Giants of Jotunheim race. He’s also a trickster, a master of manipulation that uses magic to create force fields and move inanimate objects.

In the “Earth X” alternate storyline, Loki discovers that Asgardians actually are mutants descended from ancient beings that are tricked into thinking they are immortal by the Celestials. Unable to convince Odin of his new truth, Loki stabs himself and fades away. Canonically though, Loki is considered a Norse God and not a mutant.

17 DEADPOOL

Yes, Deadpool’s first appearance was in a comic called The New Mutants #98 published in 1991, but his human origins are well established. After first appearing as a villain hired to take out Cable and The New Mutants, Deadpool’s identity changed over the years, establishing him as more of an antihero with a loud mouth.

One very human characteristic that we know about Deadpool is that he suffered from cancer. However, his accelerated healing factor means that neither his living nor cancerous cells can die, leaving him with scars all over his body underneath his mercenary suit. Although X-Men Origins: Wolverine attempts to show that Deadpool is a mutant affected by Colonel Stryker’s Weapon X program, the comics have insisted that he is human.

16 BLACK PANTHER

Born to human parents, father T’Chaka and mother N’Yami, T’Challa is definitely mortal and his parents’ demise serve as a constant reminder of that fact. His mother passed away in labor while birthing him and later, his father passed while defending Wakanda’s vibranium mound from the evil hunter Ulysses Klaw.

The Black Panther moniker is given to the leader of the Panther Tribe of Wakanda, which is passed on from generation to generation. In his early days as a leader, T’Challa even falls in love Ororo Munroe (Storm), but chooses to focus on defending his people and avenging his father’s demise. His acute senses, heightened speed, and superior strength are explained by his mystical connection to the Wakandan Panter God Bast, not because he’s a mutant.

15 JUGGERNAUT

Growing up with an abusive father in Doctor Kurt Marko, Juggernaut (Cain Marko) became jealous when his dad showed more affection towards his stepbrother than himself. Cain believed his father favored his stepbrother because he was a mutant, while Cain wasn’t. When Cain accidentally caused a fire stemming from an argument with Kurt, Kurt saved his stepbrother and later went back for Cain. Kurt did not survive, but not before warning his stepbrother to be weary of Cain.

After finding a mystical ruby in a hidden temple, Marko reads the inscription etched on it and becomes Juggernaut. His newfound inhuman strength, resilience, and ability to lift extremely heavy objects are derived from the supernatural forces in the gem.

14 SPIDER-MAN

When Stan Lee created Spider-Man in 1962, he had no idea that his new character would go on to become one of the most popular superheroes of all time. Peter Parker is a high school student who lives in Queens with his Aunt May. He’s not a mutant but was bitten by a radioactive spider at a science fair, giving him the superhuman strength and spider-like abilities, such as shooting webs and using them to swing from building to building.

Although he’s a hero, he’s constantly dealing with human issues, like being bullied at school by Flash Thompson, or fighting skewed news headlines created by editor J. Jonah Jameson. While he does indeed have special powers, he’s actually a kid trying to navigate adolescence like any other teenager.

13 POLARIS

Polaris’ origins as a mutant were well established, until Scarlet Witch cast a spell and declared “No More Mutants” in House of M #7. While Doctor Strange used his abilities to save as many mutants as he could, Polaris unfortunately couldn’t be spared. She then goes through a confusing time of trying to understand if her lost powers are real or imagined.

After being captured by Apocalypse, Polaris is recruited for The Four Horsemen and given new powers. There’s some debate on whether being a mutant, then not being one, then having similar mutant capabilities against constitutes being a mutant. We would argue no since her new abilities are due to rather to Apocalypse’s Celestial powers rather than her natural born gifts.

12 NICK FURY

Colonel Nick Fury is a human, not a mutant. He was born in New York City to a man who was enlisted in Britain's army during World War I. Fury’s role as director of S.H.I.E.L.D. – Earth’s first line of defense against unknown enemies – came about due to his experience as both a United States Army and CIA officer. He created the Avengers Initiative to help protect Earth, but he does not possess any mutant powers himself.

After an assassination attempt in 2014, Fury decided it was best if he faked his demise and allowed people to believe he was deceased. From there, he continued to lead covert S.H.I.E.L.D. programs from the underground.

11 PUNISHER

Frank Castle was a human US Marine in the army during the Vietnam War. After returning home, he was posted in New York City in order to be closer to his family. Only days later, he witnessed the end of his whole family by the mob, and of course, that set his course to becoming the one-man army vigilante The Punisher.

With Special Forces training, The Punisher became a reclusive machine hell bent on not only avenging his family by fighting crime on all levels. He wears Kevlar body armor to strike fear into the hearts of his foes and to protect his human body from fatal wounds.

10 FALCON

Sam Wilson was one of the first African American heroes to appear in comic books, debuting in Captain America #117 in 1969. Wilson was a resident of Harlem who trained a falcon named Redwing. He answered an ad for a group of men who needed a hunting falcon, but Wilson later learned that men were former Nazis now working for the evil villain Red Skull.

From 1971 to 1978, Falcon teamed up with another human hero, Steve Rogers, and trained with Captain America to fight crime in New York City. He shares a telepathic connection with Redwing, which is later revealed to have been created by Red Skull’s Cosmic Cube.

9 HAWKEYE

Clint Barton originally appeared as a villain in Tales of Suspense #57, published in 1964. His parents passed away in a car accident when he was very young and he was left as an orphan. After fleeing an orphanage with his brother, Clint caught on with a local circus where a swordsman taught him how to be an archer. He used his newly learned skills to become a travelling carnival worker himself.

He soon met fellow criminal Black Widow and fell in love, but after a failed attempt to steal technology from Stark Industries, Hawkeye decided to get clean and be a good guy from there on.

8 SCARLET WITCH

In 2015, Marvel revealed that Scarlet Witch was not actually a mutant. While it was previously believed that Wanda Maximoff may have been the daughter of Magneto, Uncanny Avengers #4 showed that she was actually born to human parents Django and Marya Maximoff and later brought into experiments conducted by High Evolutionary. She was later brought back to her parents and led to believe she had been a mutant from birth.

The failed experiments that were conducted on Scarlet Witch gave her the ability to change reality, teleport objects, and project and warp energy, among others. In the more recent Scarlet Witch series from 2016, she can also use witchcraft, a skill found in other female members of her family.

7 QUICKSILVER

Like his sister Wanda, Pietro Maximoff is born to human parents, not to Magneto as originally thought. Quicksilver was originally co-created by comic icons Stan Lee and Jack Kirby and introduced in X-Men #4 in 1964. His power to think and move at superhuman speed is also a product of the experiments he was forced to endure at the hands of the High Evolutionary.

When Scarlet Witch takes away Quicksilver’s powers, he gains the ability to jump through space and time due to the Inhumans’ Terrigen Mist. His powers are returned, however, when he sees a woman in danger and feels a strong desire to save her life. Again, it’s revealed in Uncanny Avengers #4 that he had not been born a mutant.

6 VULTURE

Vulture was co-created by Stan Lee and Steve Ditko and first appeared in The Amazing Spider-Man #2 in 1963. As a former engineer, Adrian Toomes worked with business partner Gregory Bestman until he found out Bestman had been stealing money from the company. After developing a powerful set of wings that gave him the super strength and the ability to fly, Toomes became enraged and began a life of crime in New York City.

One of Vulture’s lesser known abilities is that he’s able to artificially increase his lifespan, a power he created biomechanically himself. He is not a mutant but rather a human who turned into a merciless criminal, becoming one Spider-Man’s greatest foes in the process.

5 GHOST RIDER

Though there have been several incarnations of Ghost Rider over the years, the canonical one is a stunt rider named Johnny Blaze. Born to human parents in Washington, whom he lost at a young age. In an attempt to save his adopted father figure from cancer, Blaze made a deal with the Satanic spirit Mephisto and sold his soul to the devil.

When transforming into the hellish demon hero Ghost Rider, Blaze’s job is to punish the wicked and exact revenge on those committing evil acts. His body is still intact, however, and he uses his powers for good when possible. He’s able to withstand deadly blows since he’s considered to be immortal, but he’s not a mutant as this is due his agreement with Mephisto.

4 CLOAK & DAGGER

Cloak and Dagger, two teenage runaways who met on the street, made their debut in Peter Parker, Spectacular Spider-Man #64 in 1964. At first, Tyrone Johnson (aka Cloak) considered stealing Tandy Bowen’s (aka Cloak) purse but after another thief beat him to it, he tracked down the criminal and returned it. The two became friends but were put in danger when Cloak accepts an offer for help from some strange men on the street.

In captivity, the two were forced to endure horrible experiments using synthetic heroin by the evil chemist Simon Marshall. The tests gave Cloak and Dagger unnatural powers, such as Cloak’s ability to create new dimensions and send people to them, and Dagger’s ability to create light daggers.

3 ANT-MAN

Scott Lang was an electrician in Florida who turned to a life of burglary to combat boredom. He was sentenced to prison time but paroled years later for good behavior. After turning his life around, and even scoring a new job at Stark Industries, he broke into Hank Pym’s lab and stole the Ant-Man suit to help find the only scientist who could help cure his ailing daughter.

Pym eventually caught Lang but offered to let him keep the Ant-Man outfit if he promised to use it to fight crime. He did, and from then on he helped Iron Man and the Avengers defend Earth. Ant-Man first used gas to control his shrinking and re-growth, proving that he’s human and not a mutant.

2 VISION

Vision is not a mutant but rather an android created by Ultron. Ultron wanted to use Vision to turn on his own creator, Dr. Hank Pym, as well as his wife Janet van Dyne (Wasp). Vision is often described as a having a human body comprised of synthetic materials. The stone on his forehead is used to absorb solar energy and give him special powers.

Vision’s unique ability to change his own density allows him to fly, gives him extraordinary speed, and grants him superhuman stamina, among other things. He also has unnatural brain power, with analytical capabilities way beyond those of a normal being.

1 BLACK WIDOW

Natasha Romanova’s first appearance in comics was as a villainous Russian spy in the Iron Man comic Tales of Suspense #52, published in 1964. She was born in Russia to human parents before eventually moving to the United States to be closer to her love interest Hawkeye. She has biotechnology that helps her body heal faster and prevents aging.

In the early days, Black Widow did not have a definitive look but regularly appeared in black veil. Her special skills include espionage, hand-to-hand combat, and incredible accuracy as a sniper. Black Widow does not possess any mutant powers, instead relying on her high-tech weapons and gadgets to take down her enemies.