Superman's identity, although comically obvious at times, has been hidden from the villains in the world of DC Comics. Seeing Clark Kent in a cheap suit and glasses has been enough to fool most of those around him for years, including Lois Lane and everyone at the Daily Planet. It may be obvious to readers, but not so much for the denizens of the DC Universe.
The iconic curl of black hair and rigid jawline are seemingly hidden within the look of Kent, without raising the concern of being found out for The Son of Krypton. Not every villain has been so easily convinced by the farm boy look, though, and they actually found the connection between the Man of Steel and the Daily Planet's mild mannered reporter. Without further delay, here are 10 DC Comics villains who found out Superman's secret identity, and how they managed to do so.
10 Parasite Sapped Superman's Mind
Parasite is one of Superman's most indomitable foes. Apart from the fact that he can sap the powers of anyone that he touches, Parasite can also feed on his unlucky victim's memories.
With the ability to pry around in the brain of anyone that he touches, Parasite has easily taken control of Superman, thus easily finding out the true identity of the Kryptonian. This is a feat that Parasite accomplished in Superman: The Animated Series.
9 Hordr_Root Found It On The Dark Web
When The New 52 launched, a new villain appeared as the head of a sinister organization known as Hordr. The Hordr Organization traded in intergalactic secrets so they could essentially blackmail anyone into doing their bidding. Enter Hodr_Root, the head of this organization and later revealed as the son of Vandal Savage.
Hodr-Root seemingly found out Superman's identity in the ether of the web or traded for this information, and subsequently used it in a grand scheme to trick Superman into working for his shady organization.
8 Mr. Mxylptlk Magically Lucked Into It
It is no surprise that Superman is weak against all forms of magic, and few possess more magical ability than Mr. Mxyzptlk. The ever-powerful imp that appears in DC continuity (and sometimes Marvel) to constantly cause trouble and mischief is said to have immeasurable power. This high-level magic allows Mr. Mxy to traverse most planes and dimensions to do just about anything he pleases.
In Superman: The Animated Series, Mxy harasses both Superman and Clark Kent. It is not explicitly said how Mxy would know Superman's identity, but his endless power could have something to do with that theory.
7 Muhammad Ali Deduced It (Somehow)
Muhammad Ali is not a villain in any way, shape, or form. He did, however, have to battle Superman in a boxing match to help save Earth. Yes, really. In arguably one of the greatest moments in all of comic history, Muhammad Ali and Superman fight one another in a boxing match at the behest of an alien species called the Scrubb.
The champion of Earth is meant to fight the mightiest warrior the Scrubb have at their disposal. After Ali defeats Superman, he must now defeat the Scrubb champion, and protects Superman in achieving that feat. Ali reveals at the end of the issue that he deduced Superman's identity as Clark Kent, but vowed to keep it a secret.
6 General Zod Knew Kal-El's Father
In Man of Steel, General Zod knowing the true identity of Superman is pretty much a given. He did grow up with Kal-El's father on Krypton, after all. Although Zod is sent to be imprisoned in the Phantom Zone, he escapes when Krypton is destroyed.
Kal-El is the first natural-born Kryptonian in centuries, and that goes against the natural order of their people. It's for this reason that the disgraced general is determined to track him down no matter what. Zod tracks Kal-El through a beacon activated on a crashed Kryptonian ship, and later kidnaps and courses the information out of Lois Lane. This leads to an attack on Clark Kent's farm home that later spills onto Metropolis.
5 Dominus Read Superman's Mind
Superman has easily come under fire when enemies use any form of magic or mind-altering abilities against him. Dominus was no exception when using his telepathy to enter Superman's mind. This telepathic ability allowed Dominus to completely control Superman into dominating Earth.
In the controlling of Superman's mind, Dominus discovered Superman's greatest fear, failing the people of Earth, and discovering his true identity. Thing is, Dominus never used the secret identity of Supes in his grand scheme.
4 Batman Knows Because Superman Told Him
Batman is arguably not a villain of Superman. They have, however, gone toe to toe on several occasions (i.e. Batman: Hush, Batman v Superman: Dawn of Justice, The Dark Knight Returns, etc.). Superman and Batman knowing the true identities of each other is something they did to protect themselves from, well, themselves.
Batman is the world's greatest detective, so naturally he should have figured this secret out on his own. The revelation came in Adventures of Superman #440, where Superman finds a mysterious scrapbook that he gives to Batman. In the scrapbook, Batman discovers Superman is Clark Kent. While Superman flies off saying, "Goodbye, Mr. Wayne."
3 Lex Luthor Hacked Into The Kryptonian Ship
There is usually a great debate about whether or not Lex Luthor knows that Superman is Clark Kent. There is no mistake made, however, in the DC Extended Universe's (DCEU) first crossover Batman v Superman: Dawn Of Justice that Lex knows this.
There is no way that the movie's events (including the kidnapping of Martha Kent) would have happened if not for Luthor figuring out that Superman is Clark Kent. How was this achieved? Lex Luthor was able to download information from the crashed Kryptonian ship, and that ship could have very well held the true identity of Superman. Not to mention, Luthor is overjoyed to see Clark Kent and Bruce Wayne meet at an event so he might have known this beforehand.
2 Darkseid Just Knows (& Doesn't Care)
Darkseid is one of the most prolific villains in all of DC Comics. A ruthless warlord and mastermind, Darkseid appreciates when he meets another being of equal or greater power. Enter the Kryptonians. Darkseid knows a great deal about Kryptonians and Kal-El's heritage.
The fact of the matter is that Darkseid knows who Kal-El is, but frankly doesn't care. In the DCAU film Superman/Batman: Apocalypse, Darkseid attacks Clark Kent in his farmhouse. This would only happen if Darkseid knew that Clark Kent is Superman. Darkseid would never attack an average human at random, as he sees all of them like ants not worthy of even his smallest of efforts.
1 Brainiac Just Knows
It should be no surprise that Brainiac knows the true identity of Superman. With his Twelfth-Level intellect, it would be shocking to think that Brainiac would not be able to figure out that Superman is Clark Kent. Brainiac's brain is one of the strongest in all of comics, and this increased intelligence would lean towards Brainiac knowing all or most information in the universe.
Going back to the Superman: The Animated Series, Brainiac appears in the time-travel episode "New Kids in Town," where he plots to take out a younger Clark Kent before he becomes Superman. Brainiac already knew Superman's true identity and attempted to silence the Man of Tomorrow by assassinating him when he's but a child.