Martian Manhunter is one of the DC Universe's odd men out. On the one hand, he's vastly powerful and a member of pretty much every version of the Justice League (most of the time), yet on the other, writers just don't seem to know what to do with him. His past has been retconned several times, his personality varies by writer, and since he has more powers than Superman, he suffers from occasional mind squicks, along with frequent bouts of Forgot About His Powers and Mind over Manners to keep him from resolving plots too quickly.
He first appeared in Detective Comics #225 (November, 1955), created by Joe Samachson and Joe Certa. An alien teleported to Earth by a Freak Lab Accident, J'onn J'onzz (pronounced fairly close to "John Jones" - in Justice League his first name seems to be halfway between the English "John" and the French "Jean" and in Young Justice, it is pronounced Ja-Ahn) decided to use his abilities to help protect the innocent who could not protect themselves. All of his incarnations have that much in common (well, the DCAU, Smallville and New 52 versions came to Earth on their own, but that's a minor detail).
Comic-wise, J'onn's only had two short-lived ongoings over his existence: John Ostrander's 1998 series, which ran for 38 issues and two annuals, and Rob Williams's 2015 series, which ran for 12 issues. More commonly, Post-Crisis, he's had mini-series and one-shots: a 1988 mini by J.M. DeMatteis, a 1992 mini by Gerard Jones, a 1996 one-shot by Paul Kupperberg, a 2006 mini by A.J. Lieberman, and a one-shot crossover with Marvin the Martian in 2017 with two stories, one by Steve Orlando and Frank J. Barbiere, and one by Jim Fanning.
Factors that have varied greatly over the decades include whether he is actually the Last of His Kind, whether J'onn J'onzz is his real name, whether the green humanoid form he normally assumes in public is his true appearance, whether his memories of Mars are real or fake, and whether his Weaksauce Weakness to fire is psychological or physiological.
His powers vary tremendously, even within a single incarnation. In his earliest proto-Silver Age appearances, he worked mainly with Psychic Powers (and writers kept coming up with newer and sillier applications as the Age got more Silvery — like mental ice cream creation and sonic finger-snapping). Since then he's mainly been treated as a Flying Brick with a few extras.
J'onn was seemingly absent during the events of The Death of Superman, only for it to be revealed that he had taken on the identity of Bloodwynd, the newest member of the JLA at the time. The real Bloodwynd had been imprisoned in his own blood gem by Rott, the evil spirit dwelling in the gem, and when J'onn had tried to help free Bloodwynd, Rott had used his own power to brainwash J'onn into becoming Bloodwynd, and seek out a means to bring Rott back into the real world. When the League learned the truth, they helped to defeat Rott and free Bloodwynd, restoring J'onn to normal in the process.
In his 1998 series, Ostrander revealed that J'onn largely functioned as the "Superman" of the Southern hemisphere, operating as its most recognizable hero,note as well as maintaining numerous assumed identities the world over, including being a regular cab driver for Clark Kent.
To the non-comic-geek public, he is best known for his role on the Justice League and Justice League Unlimited animated series, where he was voiced by Carl Lumbly. He appears in Batman: The Brave and the Bold as Batman's close friend, and acts as the Only Sane Man in a number of episodes before appearing years later in Scooby-Doo! & Batman: The Brave and the Bold. He has also popped up in The Batman, voiced by Dorian Harewood, on Smallville where he's played by Phil Morris, and the So Bad, It's Good aborted pilot, The Justice League of America, where David Ogden Stiers (Dr. Winchester from M*A*S*H) filled the role. The animated film Justice League: The New Frontier had MM voiced by Miguel Ferrer. He's also appeared in the animated Young Justice as Miss Martian's uncle, voiced by Kevin Michael Richardson, in Lego Batman 2: DC Superheroes, voiced by Cam Clarke, and in Supergirl (2015), played by David Harewood. It was revealed in October 2019 that he was to be featured in the Justice League filmnote , but he was cut from the theatrical version. He is set to appear in the director's cut, Zack Snyder's Justice League.
As part of the DC Comics New 52 relaunch, he became one of the central characters of Stormwatch and lost most of his friendliness, relationships to other DC characters, and love of Oreos. He left after issue 12, wiping his teammates' memories of him in the process, and went on to lead the 2013 Justice League of America. He got the love of biscuits back in the Williams series (it's hard to know how else to interpret having an entire persona obsessed with biscuits, to the point of calling himself Mister Biscuits), and his relationships to other characters came back from Dark Nights: Metal on.
Powers used by the Martian Manhunter are a mixed bag with no cohesion that nonetheless makes him very formidable; the ones common to most incarnations are: Super Strength, Super Speed, Nigh-Invulnerability, Flight, Voluntary Shapeshifting, Healing Factor, Invisibility, Intangibility, Psychic Powers (mainly Telepathy, Telekinesis and Nine Senses, which are poorly defined and often ignored by most writers) and Eye Beams (referred to as "Martian Vision"). See the characters page for more info.
Note that all these are subject to change without notice; in the telefilm, J'onn could just barely shapeshift and demonstrated no other powers (it was a very low budget show), but had no problem with heat. The Smallville Manhunter can't heal within Earth's atmosphere, can project heat from his palms and remains almost exclusively in human form. The JLU version lacked speed, invisibility, Eye Beams and his nine senses and weakness to fire was only implied.note Young Justice also nixes the Eye Beams and nine senses and portrays the weakness to fire (or any extreme heat) as being a side effect of living on a colder planet.note And so forth.
Other Tropes associated with him:
- The Ageless: He can certainly be killed, but if Martians age at all, it must be incredibly slowly. New 52 "Conehead" J'onn is over 200,000 years old; in the Williams series, he's somewhere over a million.
- Alien Among Us: How much he has to hide his heritage varies from writer to writer. While part of the Justice League International this was dropped altogether. In fact, Batman nominated J'onn his successor as leader because he felt that J'onn had a better public image.
- Aliens Love Human Food: J'onn develops an addiction to Chocosnote some time after he visits Earth. At one point it got so bad that after being deprived of them he goes into withdrawal and throws a tantrum as a rampaging monster. Unlike most examples, this one is actually justified as Batman discovers Chocos produce a chemical reaction in Martians similar to addictive narcotics.
- Alliterative Name: Both his real name and his codename.
- The Aloner: In some continuities, J'onn not only is the last Martian left, but he's conscious and active by himself for an indeterminately long time before coming to Earth.
- Apocalypse How: Pre-Crisis, Mars was fine... right up until 1969's "And So My World Ends", when Commander Blanx engineered a Class 6 Apocalypse by setting Mars on fire and leaving it a lifeless, barren husk. In Post-Crisis continuity, the planet suffered a Class 3, with Malefic's plague, H'ronmeer's Curse, wiping out every Green Martian but leaving the rest of the planet intact. In New 52 continuity, it suffered a Class 6 due to environmental collapse, a consequence of the Martians' insatiable greed at their planet's expense.
- Archenemy: Malefic — and sometimes Despero — is typically seen as J'onn's by the fanbase. Pre-Crisis, Blanx held the title for similar reasons.
- Artifact Title: The name Martian Manhunter, considering that he doesn't do as much detective work and became more of a straight alien hero.
- Ax-Crazy: Malefic again. He's basically the Martian version of The Joker, only with less humor and more Mind Rape and torture. He is usually credited as the one who wiped out the rest of the Martians.
- Bald of Awesome: J'onn and most other Green Martians.
- Bald of Evil: B'rett, B'enn B'urnz, and Malefic. Also Blanx and the majority of White Martians.
- Bash Brothers: With Superman and Aquaman.
- Beware the Nice Ones: Generally The Quiet One of the Justice League, and way, way down low on the "will use extreme violence" list. But actually piss him off, and you'll quickly remember that he's on equal footing with Superman for all-around power, plus he can transform into ANYTHING he can think of, and one of his basic abilities is Mind Rape.
- Cain and Abel: J'onn's archenemy is his fraternal twin brother Malefic in Post-Crisis continuity.
- The Cape: Amongst the greatest of Capes, but not as well known as Superman or Batman.
- Chest Insignia: During Brightest Day, J'onn had a red circle depicting Mars. Post-Flashpoint, he's had a red circle divided into eight parts. You could make a case for the red 'X' of his original costume as well.
- Chrome Dome Psi: Just like Xavier.
- Chuck Cunningham Syndrome: Jupiter, J'onn's dog who was introduced in one early story and then completely forgotten.
- Civil War: Mars has been engaged in a few. Pre-Crisis, J'onn was actually a leader in the Martian Civil War, leading the Desert Dwellers against Commander Blanx's Pole Dwellers for control of the Blue Flame of Mars.
- Combat Pragmatist: Commander Blanx. He's always got a gun hidden on him somewhere, cheerfully attacks from hiding, and brings in an ally to club J'onn from behind in their duel.
- The Comically Serious: Except during the Detroit era, when he became something of a Deadpan Snarker. Lampshaded by Firestorm during Crisis on Infinite Earths of all things:Firestorm: Don't you ever feel cold with those clothes, J'onn J'onzz?
Martian Manhunter: Martians feel no cold. Why do you ask?
Firestorm: Geez, Mars doesn't need women. It needs a sense of humor.
- An alternative interpretation is that he's always a Deadpan Snarker, but most of the time (including in the example above) nobody notices.
- Commanding Coolness: Averted by Commander Blanx, a genocidal sociopath.
- Continuity Drift: In his first story, "The Strange Experiment of Doctor Erdel!", J'onn, masquerading as a human named John Jones, goes sightseeing around the world, comparing his observations to life on Mars. At one point, he mentions in passing a "Great Evolution", which eradicated crime on Mars for centuries. Later stories featured Martian criminals, though they were still treated as significant aberrations.
- Cool Mask: Mr. V, although it's actually a pretty lame mask.
- Cowardly Lion: Commander Blanx. He's a Dirty Coward who prefers to let his men do the fighting, and has no problem bringing in an ally to sucker punch J'onn In the Back in what was supposed to be a man-to-man duel. He'd rather run than fight, and has a healthy respect for his own skin. All that being said though, when he's cornered he proves himself a perfectly capable combatant, nearly killing J'onn, and at one point, throwing down with Superman while on Earth.
- Dark and Troubled Past: Considering what J'onn endured, Post-Crisis — witnessing the horrible deaths of his entire race, including his wife and child, and then wandering completely alone through a wasteland, possibly for eons — it's a testament to J'onn's willpower that he's even still sane. Though he may feel like a Fish out of Water here and sometimes gets frustrated with us, he loves Earth and is enormously grateful to be among living people again. (In the Williams series, his sanity is rather more fragile, as he coped with the trauma of his origin by forgetting himself repeatedly during the million-odd years he's been on Earth.)
- Dead Person Impersonation: His iconic "John Jones" identity belonged to a dead cop. It became his preferred method of adopting secret identities in the Ostrander series, stepping into the life of someone who'd died before their time.
- Death by Origin Story: He has what is arguably the most extreme example of this ever in Post-Crisis continuity. Most of his species, including his wife and daughter, spontaneously combusted after contracting a psychic plague engineered by his own brother. J'onn only survived by severing his own psychic connection to the rest of his people, meaning he had to watch his family die in front of him while he was mentally cut off from them. The worst thing is that he could have stopped all of this. He knew his brother was up to no good, but J'onn still had misplaced trust in him and underestimated the depths of his evil. The loss of his people and his family in particular are a huge part of his character, which might be why attempts to revive his race always turn out to be fakeouts. While there is another (evil) Green Martian out there, his family is still dead.
- Depending on the Artist: NOBODY can agree on what his true Martian form looks like. Luckily, Martians are shapeshifters, so it doesn't really matter.
- A minor point is whether his eyes are normally solid red or solid black.
- Diabolical Mastermind: Mr. V, alias "Faceless", leader of the crime syndicate Vulture, who J'onn tangled with frequently in the fifties and sixties.
- Dirty Coward: Commander Blanx. Overlaps with Combat Pragmatist and Cowardly Lion.
- Distaff Counterpart: J'onn's young counterpart on the Teen Titans, M'gann M'orzz, aka Miss Martian. She's actually a White Martian who's turned her back on her people's evil ways.
- The Dreaded: There's a reason why Despero scares everyone shitless: because he's an endlessly hateful, world-demolishingly-powerful juggernaut who usually requires multiple teams just to slow him down. Pitting a single team against him is likely to result in the death of everyone in it unless it contains some serious heavy hitters.
- Duel to the Death: "And So My World Ends" concludes with a climatic trident duel between J'onn J'onnz and Omnicidal Maniac Commander Blanx.
- Emerald Power: He's as strong as Superman.
- Evil Counterpart: Commander Blanx, pre-Crisis on Infinite Earths. Other evil Martians showed up, but none contrasted with J'onn quite the way that the utterly cold-blooded Blanx did. One could make a case for the non-Martian Despero being another Evil Counterpart, with his Telepathy, history of persecution, and truly alien status.
- Evil Twin: Ma'alefa'ak (alias Malefic) is literally J'onn's Evil Twin post-Crisis.
- Exposition of Immortality: The Manhunter has reminisced about his time on Mars prior to the accident that led to him being teleported to Earth in the 50s, which has shown that he was alive on Mars during the 18th century. His unchanging appearance is credited to Martians being very slow-aging.
- Expy: Malefic to Commander Blanx. Both are Martian leaders with a link to J'onn who chose to wipe out 99% of their own species. They are very different in personality and motivations though, with Malefic being an Ax-Crazy Serial Killer and Mind Rapist, while Blanx is an utterly apathetic sociopath who did it for the money. One could argue that the current White Martians are, as a species, Expies of Blanx's Pole Dwellers.
- Fantastic Racism: Green vs. White Martians. And Red vs. White Saturnians, the Martians' bio-engineered sister species. Note that originally, this wasn't so much racism as nationalism, since Martians of both kinds can alter their color at will. Only in recent years have they been defined as separate species (and then again as one species split in two — It Makes Sense in Context, sort of.)
- Fat Bastard: Mr. V.
- A Form You Are Comfortable With: It's been established since the DeMatteis mini in the '80s that J'onn's familiar green skinned muscleman form is a compromise between a human form and his true natural form (which is gaunt, occasionally finned, and significantly less human looking.) The reason he doesn't go all the way with this trope is because he can more comfortably maintain this form for longer periods of time.
- Funny Animal: The "Martian Anteater," J'onn's Earth-C-Minus (well, "Mars-C-Minus," I suppose) counterpart and a member of his world's "JLA" (the "Just'a Lotta Animals)."
- Galactic Conqueror: Despero, a Justice League villain, who nevertheless has a major hate-on for J'onn. Whenever he targets the team, J'onn is usually the first one Despero wants to kill.
- Genocide from the Inside: J'onn's brother created a psychic plague that killed off the Martians.
- G-Rated Drug: J'onn was very fond of Oreos (later named Chocos, obviously due to copyright issues) during Giffen and DeMatteis' humorous run on Justice League International in The '80s. When Blue Beetle and Booster Gold hid these cookies (in a flashback written by John Ostrander), much rampage ensued. This becomes a Tear Jerker when a Choco cookie is placed by Batman on his coffin at the end of Final Crisis: Requiem.
- The Heart: Of the Justice League.
- Heroic Willpower: Post-Crisis, the Martians were wiped out by a psychic plague that caused the victim to shapeshift into a form that would spontaneously combust. The only way to save oneself was to avoid telepathic contact with anyone, an almost impossible feat for a race that maintained low-level esper contact constantly. J'onn survived because he was able to hold out the longest without telepathic contact, tragically leaving him as the last man standing. J'onn survived because he was literally the strongest-willed person on his planet.
- I Always Wanted to Say That: In Martian Manhunter Annual #2 (Oct. 1999): "You're probably wondering why I've called you all here today..." Thinking to himself: "Call me whimsical if you must, but I've waited years for the appropriate time and place to say that."
- Insufferable Genius: Prof. Hugo, a pre-Crisis Mad Scientist who demanded recognition from the world.
- It's Personal: With Blanx pre-Crisis, with Despero and Malefic in the later years.
- The Juggernaut: Despero following his most recent power-ups.
- Karmic Death: Commander Blanx, who engineered the Martian apocalypse pre-Crisis, gets crushed to death beneath a globe of Mars.
- Kill All Humans: Blanx and Malefic both display this attitude towards their fellow Martians.
- Kill It with Fire: Martians are weak against fire. Pre-Crisis, Blanx used the Martian Blue Flame to execute this strategy against the planet as a whole. That's right — he set Mars on fire.
- Knight of Cerebus: Blanx may only have appeared for one issue, but he's still this, as his crime forever changed the tone of Martian Manhunter stories from traditional lighthearted sixties fare to introspective angst, and helped usher in the Bronze Age of comics in the process.
- Last of His Kind: More or less. In Real Life, after Mariner and Viking proved Mars to be a wasteland, DC had to explain how this had happened and what became of J'onn's people. The exact nature of the catastrophe and how many survived it has varied over the years. (That said, although the Green Martians are functionally extinct, the White Martians continue to survive.) Their bio-engineered progeny, the Saturnians living on Saturn's moons, are still around, although they don't take much interest in Earthling affairs. Jemm, Son of Saturn, is the most well-known.
- The sole exception to this since the Silver Age has been Young Justice, where Mars is still inhabited and J'onn has numerous nieces and nephews.
- Literal Split Personality: In the Williams series, J'onn split himself into multiple independent personae with their own bodies, only some of which were aware of their origin.
- Mad Scientist: Professor Arnold Hugo, a pre-Crisis enemy.
- Martians: It's in his name.
- Master of All: Has many of the powers of Superman, plus Telepathy, Intangibility, and Voluntary Shapeshifting. He does have a Weaksauce Weakness, but he has been known to overcome it.
- Mind Rape: A major crime on Mars; Malefic is naturally guilty of it. Despero is also very fond of this, and has inflicted it on J'onn on numerous occasions. J'onn once forced this on himself. To be fair, the process forcing it was an attempt to force sanity into The Joker's skull. And it worked, if you can believe it. Only for a few seconds, but still.
- Mission Control: One of his most essential roles in the Justice League. Thanks to his keen intellect, strategic mind and psychic powers, J'onn can serve as kind of switchboard operator, keeping the other members of the League in mental communication through him to coordinate strategies and maneuvers during battle. If any villain gets scared shitless because the League fights like a well-oiled machine, J'onn is the reason. He also often serves as dispatcher, choosing members of the League and transporting them to where they're needed as the situation demands (this was his main role in Justice League Unlimited).
- Monster Modesty: If he wanted to, he could easily shape-shift a nice suit to wear. Instead, he runs around in underwear and a cape. This was his policeman's (or "manhunter's") uniform on Mars. Since the Lieberman mini's redesign, he's at least started wearing pants.
- Multiple-Choice Past: In the comics, J'onn changes pasts with practically every writer, and every adaptation has felt free to come up with their own version.
- My Suit Is Also Super: In John Ostrander's run, it's established that the telepathic, shapeshifting Martians wear clothes that are actually bioengineered organisms that shapeshift in accordance with the wearer's telepathic commands.
- New Powers as the Plot Demands: Especially during the Silver Age. To the point of using "all the powers of space" to create an ice cream cone with his mind.
- Not So Above It All: In JLI. He may be serious and straight, but he's not beyond enjoying oreos.
- Older Than They Look: In John Ostrander's run, it's never established just how long ago the Martian Apocalypse happened (J'onn apparently isn't sure himself), but the implication is that he was left wandering around a lifeless world, barely maintaining his sanity, for a very long time until Dr. Erdel's teleporter accidentally saved him. In Rob Williams's run, after being blasted to Earth following the Apocalypse, he spent over a million years wandering the planet.
- Only in It for the Money: Why Blanx wiped out Mars in the Silver Age.
- Only Sane Man: In JLI, especially after Batman left.
- Person of Mass Destruction: Despero, after being reborn in the Flame of Pytaar, added Playing with Fire, Mind over Matter, Reality Warper, and Super Strength, Super Speed, and Nigh-Invulnerability to his already considerable Telepathy. These days he's a walking engine of destruction, who requires the entire League to put down.
- Playing with Fire: The Human Flame, and post-rebirth, Despero.
- The Power of Hate: Despero runs on it.
- Primary-Color Champion: Downplayed - his classic outfit consists only of a few primary-colored strips over his green skin. Blue cape, red straps across his chest, yellow buckles and belt. His more modern outfit adds a lot more black.
- Prongs of Poseidon: Employed by J'onn and Blanx both during their Duel to the Death.
- Psychic Radar: The Manhunter can use his telepathy to pinpoint the location of a desired individual, at some pretty fantastic ranges. Just as well, since he generally has to fly up into orbit in order to not get confused by all the ambient thinking.
- Race Lift: An unusual case. J'onn's first Secret Identity in the comics, John Jones, was a white man. However, since around the time of Smallville, where he was played by Phil Morris, J'onn's tended to have a primary secret identity as a black man, whether it's John Jones or someone else.
- Real Men Wear Pink:
- J'onn is a stoic but sensitive Warrior Poet who loves eating Choco cookies.
- As noted below, he had an identity named after Sailor Mars.
- Secret Identity: In the Silver Age, J'onn J'onzz masqueraded as mild-mannered John Jones, a name no one could have possibly guessed.
- Just one throwaway line◊, but it's to Sailor Moon of all things Paving the way for Miss Martian later on.
- And what appears to be one to the Hulk in this. J'onn is addicted to cookies, two of the other superheroes hid them in a prank. Hilarity Ensues. This was a imaginary story, sadly.
- Martians call their planet Ma'aleca'andra, a reference to Malacandra, the Martians' name for their planet in C. S. Lewis' The Space Trilogy (though J'onn's name for Earth is Perelandra, which was Venus in The Space Trilogy; Earth was Thulcandra.)
- In 1952, David Starr, Space Ranger created John Jones, the colonial Martian farmhand who becomes a heroic sidekick, and Telepathic Spacemen ancient (native) Martians who moved beneath the surface of Mars once it became uninhabitable. Martian Manhunter was created in 1955, and the titular character is named J'onn J'onzz, (he would anglicize it to John Jones as an alias) in an allusion to the work by Paul French.
- The Sociopath: Blanx and Malefic.
- Space Police: Back on Mars, J'onn was a "Manhunter," which is basically a very high-profile policeman. His mother was one, too.
- Spiritual Successor:
- White Martians to Pole Dwellers; arguably Malefic to Blanx.
- In the Bronze Age, Jemm: Son Of Saturn was created because the writer wanted to do a story about J'onn and couldn't get editorial permission. Post-Crisis, it was established that Jemm's race is a bioengineered offshoot of J'onn's race (and, unlike the Martians, they're still thriving).
- The Spock: Calm, Composed and Patient. If he Batman had a competition on who could keep their face the blankest under fire neither would win.
- Straight Man: To Booster Gold, Blue Beetle and the JLI in general.
- Sugar-and-Ice Personality: He's not consciously trying to seem aloof; Martian mannerisms are just different. J'onn's really a softy at heart, but people have to get to know him before they realize it. He's also surprisingly funny and whimsical, according to Martian standards, anyway.
- Superhero Speciation: Adaptations tend to focus on the abilities he doesn't share with Superman or Wonder Woman. While he's still tough, expect to see his shapeshifting, telepathy and intangibility get favored over brute strength.
- Superman Substitute: Despite being on first-name terms with the man himself. The twists are that he personally lived through the loss of his world, his weakness is a lot more common, and he's clearly alien in appearance (although he can get around this by shapeshifting).
- Superpower Lottery: Although the extent of his powers varies depending on the writer, J'onn is usually portrayed as one of the half dozen or so heroes considered more powerful than Post-Crisis Superman (Pre-Crisis Superman was even too much for him). The Flying Brick portion of his powers are roughly equal to Superman, plus there's all those other abilities he's got.
- Super-Powered Evil Side: Know why J'onn and all Green Martians have a fear of fire? Well... it's a psychic block implanted by the Guardians of the Universe to keep their extremely powerful, extremely evil Burning Martian selves held in check.
- The Syndicate: Vulture, a criminal conspiracy from the sixties, led by the enigmatic Mr. V. It had agents scattered throughout Europe, and regularly stole weapons technology, missile codes, and top-secret documents in addition to the standard gold, jewels, etc. The organization was broken up into cells, with each cell being led by one of Mr. V's Body Doubles.
- Telepathy: J'onn's most frequently used power these days. It's shared by all other Green & White Martians (save Malefic), and by Despero, who also features Mind over Matter, Playing with Fire, and Reality Warper abilities.
- Trademark Favorite Food: Oreos - or rather, Chocos.
- Unfinished Business: J'onn with Malefic, Despero with J'onn.
- Weaksauce Weakness: Fear of fire. Martians are actually less vulnerable to fire than humans, and because of their shapeshifting abilities, can recover very quickly from any injury that they survive. The problem with fire is that they are terrified of it, and just being near a lighter can render them helpless. J'onn J'onzz himself has been on earth for decades, and no longer has such an extreme reaction to it. The fear of fire is actually a psychic barrier the Guardians of the Universe put into the Green Martians to stop their psychotically powerful Burning Martian selves from taking over the universe. J'onn's is called Fernus, and he was capable of nearly killing the entire Justice League all on his own, with J'onn mystically chained inside his head. Alternatively, J'onn's fear of fire is caused by him having witnessed his entire family being burnt to death, and is therefore not a Weaksauce Weakness but a form of Post-Traumatic Stress Disorder. It is pointed out that this weakness is not physical at all when his version of Flashpoint - which is ostensibly the same as his mainstream one, except without the whole heroic path his life took - mentions that he used to be doused with fire by the Russian soldiers who kept him in captivity. This was so frequent that he eventually found out the fire didn't really cause him any harm, and when he did... Well, let's just say it didn't end well for the Ruskies. It seems to be both physical and mental with his Young Justice incarnation. In the course of one episode, J'onn phases through a fire arrow from Red Arrow, but he was still affected by it, and Miss Martian shut him down completely by showing him a vision of him surrounded by flames.
- Wham Episode: "And So My World Ends ", the Silver Age story which saw Blanx kill off all life on Mars, saw J'onn leave the Justice League to lead his few surviving people, and forever changed the tone of all Martian Manhunter stories.