When you think about the heroes of Marvel or DC, it might be obvious who belongs in which universe. The world of the Justice League and Teen Titans is very different from the one of the Avengers and X-Men. However, when it comes to the power-sets of the characters, there is a lot of crossover. A superhero is a superhero, regardless of the flavor of their respective universes.
We are going to take a look at a handful of superheroes from DC and Marvel, and then the alternate version that was copied by Marvel or DC, respectively.
Flash / Quicksilver
Who doesn’t love a good Speedster? In 1939, the Flash was written by DC comics, the third superhero (that is still in publication) after Superman and Batman, and helped establish the original Justice League team.
It was much later in 1964 that Quicksilver was created by Stan Lee, as a mutant and son of Magneto.
During the JLA/Avengers Crossover, it was determined that The Flash is indeed faster than Quicksilver.
Namor / Aquaman
In 1939, Marvel Comics #1, the Sub-Mariner appears, and quickly becomes one of the top three heroes of Timely Comics (Marvel before Marvel), alongside Captain America and The Human Torch (then an android). Son of human sea captain and Atlantean Princess, Namor has been both with and against popular heroes, depending on how each conflict relates to his kingdom of Atlantis.
Shortly after in 1941, Aquaman was originally written as a side-story character, but quickly gained popularity. It wasn’t until the ’90s that writers started to seriously look at his role as the King of Atlantis. And yes, in some versions his father was a lighthouse worker, and mother was a princess of Atlantis.
Robin / Bucky
In 1940, about a year after Batmans debut, Robin the Boy Wonder was introduced as a way to gain younger readers, which he did. The subscriptions doubled with his introduction, and Robin has been part of the BatMythos ever since. Robin was intended to be a Watson to Batman’s Sherlock Holmes, but kid Robin never had the same intellectual input that Watson did. Instead he filled the more acrobatic abilities, leaving Batman more of the brawler.
In 1941, Captain America is fighting against the Nazis, as Marvel is trying to convince the American public that we should join World War II. He also gained a young teenage sidekick named Bucky Barnes, who again was a bit more acrobatic than Cap was. Stan Lee later mentioned he never liked the teenage sidekick shtick, but by that point Bucky was long dead.
Atom / Ant-Man
In 1940, DC created the hero The Atom, who was a physicist that was very short, but had super strength. Unfortunately, he wasn’t much more than that. It wasn’t until his second iteration in 1961 that he gained the ability to shrink down
Of course it was the very next year, 1962, that Marvel unveiled their new hero Ant-Man, who again could shrink down to the size of an ant, but also had the ability to telepathically communicate with ants.
Catwoman / Black Cat
1940, Batman #1, Selina Kyle Catwoman makes her first appearance as one-part villain, one-part romantic interest for Bats. As she has gone back and forth from villain to hero to girlfriend, Catwoman has been one of the most popular characters in Batman, finding herself on lists of top comic characters, both hero and villain.
In 1979 Marvel introduced Black Cat into the Spider-Man comics, and she has made the same rotations through hero and villain, as well as romantic interest for Peter Parker. The creator claims that he wasn’t thinking of Catwoman at all when he created the character, but instead of a character from a 1949 MGM cartoon, about a cat who, when he crosses the paths of others, bad luck inevitably follows.
Green Arrow / Hawkeye
In 1941, Oliver Queen was written as a Robin Hood type hero, even though he was a wealthy business man, not unlike Bruce Wayne. Armed with nothing but a bow and some trick arrows, he was fun, but not overly popular, until he lost his wealth, and became a voice for left-wing politics.
Once again in 1964, Marvel created Hawkeye, originally a villain. It wasn’t long however until he joined the Avengers. While it might be strange to see a good archer next to gods among men, as Hawkeye joined/founded other SuperTeams he was able to make a spot for himself. However many agree his best comics are those when he is alone.
Plastic Man / Mr. Fantastic
1941, DC decides to introduce some humor into their superhero lineup. Plastic Man had the powers to stretch and contort his body, from as small as an ant, to as large as a skyscraper, to as flexible as a rubber band, to as dense as a rock.
In 1961, as Stan Lee was thinking of leaving Marvel Comics, his wife told him to write one last story that he really wants to, and so he creates the Fantastic Four as a way to tell stories about heroes that had faults, bad days, and petty arguments, stories he wanted to tell. So he created Mr. Fantastic, who had all the same powers as Plastic Man. He also wrote Sue Storm, who had the same powers as The Invisible Man, recreated The Human Torch from Marvel history, and a rockman. None of these characters were super creative, because they were more about their family dynamics.
Deadshot / Bullseye
1950, DC creates the ultimate assassin, who never misses a shot that he takes, to be the villain of Batman. I wish there was more to say, but this is pretty much it.
Then in 1976 Marvel makes their own evil marksman, but one that almost refuses to use guns. He prefers shurikens, knives, even playing cards. They give him to the closest thing Marvel has to Batman; Daredevil.
Martian Manhunter / Vision
In 1955, DC creates one of the original seven members of the Justice League, Martian Manhunter, one of the most powerful beings alive. His powers changed as needed by the writers, but filled many Superman roles in the Justice League, because Superman was busy with his own solo comics (in the same way that Green Arrow did with Batman).
In 1968, Marvel comics creates The Vision, an android created by Ultron, using the body of the WWII android The Human Torch. While it might seem like this is a copy like all the others, Timely Comics actually had a character in 1940 called Vision (Aarkus), who was a superpowered alien. So this time, DC actually copied Marvel, though it initially appears the other way around.
Darkseid / Thanos
In 1970, Jack Kirby (from Marvel) went and did some work with DC Comics, and started working on his multi-title story Fourth World, which included the concept of the New Gods, a race of superpowered people, stronger than anyone from Earth, and Darkseid was their leader.
Then in 1973, Jim Starlin wanted to make his own super-evil character from another world, and based it off of…Metron. A skinny, brilliant villain, from the New Gods. Then editor Roy Thomas said “Beef him up! If you’re going to steal one of the New Gods, at least rip off Darkseid, the really good one!”
Man-Thing / Swamp Thing
This one is a close call. Len Wein is the creator of DC’s Swamp Thing, and his roommate was Gerry Conway, the creator of Marvel’s Man-Thing. The characters were first introduced within two months of each other in 1971.
They claim that they each didn’t know the other was creating a swamp based monster character, though they were both basing their characters off of a 1942 character The Heap. I personally find it hard to believe that they both, simultaneously, created near-identical characters from the same inspiration, without knowing it was happening. But the world will never know.
Deathstroke / Deadpool
In 1980, DC already had their assassin Deadshot, but they wanted a more developed villain, a villain that broke the rules of fictional villains. He didn’t just kill people for money, he shoved radioactive Kryptonite into his daughters eye socket, he went as far as sleeping with an underage girl, specifically to get under the skin of his enemies, the Teen Titans.
Then in 1991, Rob Liefeld was creating a new character for the X-Men, and he was admittedly a fan of the Teen Titans. When co-writer Fabian Nicieza saw the art, he told Liefeld that is was just Deathstroke. So they decided to play with that similarity, and named him Deadpool, Wade Wilson (Deathstroke is Slade Wilson), and gave him the same weapons of two katanas with a bunch of guns.
Winter Soldier / Red Hood
In a twist of events, this is again Robin and Bucky, but flipped in continuity. There was a common phrase in comic fandom “No one stays dead in comics, except Bucky, Jason Todd, and Uncle Ben.”
In 2005 Marvel Comics brings back young Bucky Barnes from death. However, he has come back as a murderer and Cap villain. It turned out that his body was recovered by Soviet spies, who brainwashed him and continuously froze and thawed him over the past half century, so he can commit assassinations, then not be there for the punishment.
In 2006 DC Comics brings back young Jason Todd from death. However, he has come back as a murder and Batman villain. It turned out that his body was recovered by Ra’s al Ghul via the Lazarus Pit, which heavily alters your emotions and mental stability. He returns, angry that Batman let the Joker live after killing Jason, and decides that Batman is too soft on the villains of Gotham.
Marvel and DC are aware of their similarities, and so in ’96, they created Amalagam Comics, wherein they created superheroes that were literally an amalgamation of each of their individual heroes. This is also where the DC vs. Marvel miniseries came from.