In 1955, the Martian J'onn J'onzz was accidentally teleported to Earth in Dr. Saul Erdel's observatory outside of Gotham City, due to Erdel's experiment, which was meant for making contact with alien radio signals. J'onn J'onzz's appearance shocked Erdel, who then suffered a fatal heart attack. Before dying, Erdel apologized J'onn for stranding him and warned him to keep himself hidden as human society will fear and hate him because of his appearance.
J'onn J'onzz then took the identity of Erdel and lived in his apartment for some time in order to study Earth society through television. Finally, J'onn took the identity of a film noir detective as John Jones. By 1957, J'onn became a very renowned detective among Gotham City's Police Department, where he befriended and partnered with Samuel "Slam" Bradley. Though J'onn's peers saw him as very somewhat naive (due to the fact that he imitates characters and actors from television) and peculiar for studying unusual subjects such as aliens and racial civil rights during that era, in which he grew fascinated with John Henry.
During a case of a missing industrialist's son, J'onn and Slam Bradley's investigation led them to a cult that worshiped a being called The Centre, who were planning to sacrifice the boy. The two unexpectedly found the Batman already there battling the cultists. During the struggle, J'onn was momentarily weakened when a fire broke out, which was then put out by Slam. After the cultists were defeated, J'onn and Slam listened to the cult's leader of the impending doom of the Centre. J'onn became more curious of the Cenre cult that have been appearing around the world and have been trying to unlock a book that the Cult possessed, which may contain more information. After returning home from watching a movie, J'onn was personally confronted by the Batman who then revealed to him that he had also been researching the cult and provided J'onn a talisman that he obtained from the cult that he believed that J'onn could decode. Before leaving, Batman revealed to J'onn that he had been spying on him and learned that he wasn't human. But also, he knew his weakness to fire and told him he would not hesitate to use this weakness should he ever betray him. At the GCPD, J'onn discovered that the talisman was a key to the cultist's book and unlocked it, finding stories and reports of the cult's foreboding entity, the Centre. As J'onn touched an image of the Centre, J'onn discovered that this being lived on Earth and planned on eradicating mankind.
By 1958, J'onn was needed to interrogate Ferris Aircraft engineer Harry Lieter, who was brought in for killing his mother and shooting a police officer. During the interrogation, J'onn learned from him about Task Force X's information of hidden Martians "taking over the Earth." His interrogation was interrupted by government agent King Faraday, who came to arrest Lieter. After Faraday befriended J'onn, the Martian mentally learned from him about Project Flying Cloud's space flight to Mars.
While drinking at a regular bar with Slam Bradley, J'onn watched the news and very dismayed to learn of John Henry's death by the Ku Klux Klan. J'onn returned to his apartment, shaken of Henry's death because of racism, and sought console by watching television. He then viewed the Flash's sudden appearance who announced his retirement because of the American public's growing fear and distrust of their own heroes. Flash's retirement finally convinced J'onn to give up all hope in humanity and leave Earth through Flying Cloud. J'onn then met with Batman at the GCPD's rooftop and giving every information he had found on the Centre to him. Thereafter, J'onn had one final farewell from his friends James Gordon and Slam Bradley.
J'onn traveled to the launch site of Flying Cloud, but he was spotted and confronted by King Faraday at gunpoint. J'onn subdued Faraday, but as the rocket was about to launch, he abandoned his chance to leave Earth and rescued Faraday from the rocket's afterburner, severely weakening himself in the process. He later awakened and found himself imprisoned underneath Nellis Air Force Base where other "mystery men" are held. Faraday was waiting for him, and asked J'onn as to why he saved him. J'onn replied that he couldn't let any living thing to die. Also, after knocking out Faraday he looked into the agent's mind (and heart), he was moved to have found that Faraday was pure of heart and believed that one day the world wouldn't be living in fear and hate. And that filled J'onn with renewed hope for humanity, much to Faraday's self-astonishment.
During his imprisonment, J'onn was treated fairly well and was given the chance to leave. He bonded with Faraday, and the two often played a friendly game of chess. The two knew about the coming threat of the Centre entity, which had appeared near Cape Canaveral, Florida. J'onn was mentally burdened by the Centre's powerful mental presence that propagate across America, but managed to keep its influence away. He was then asked by Faraday to accompany him to Canaveral. He accepted and adopted a new Martian/human superheroic hybrid form as the Martian Manhunter, in order to have a more friendlier appearance. However, he changes his costume to an impressive government agent guise at Faraday's request.
The two arrived at Cape Canaveral where Superman rallied both heroes and normal soldiers to put aside their differences and work together, and Faraday seconded for Superman and introduced him to J'onn. After Superman confronted the Centre, J'onn and the others witnessed Superman's apparent demise. Jónn was overcome by the Centre and fell unconscious to its influence. As his condition was weakened, J'onn was watched over by Challenger June Robins. J'onn soon recovered and watched the heroes and soldiers commence their two-stage assault on the Centre. The base was then attacked by the Centre's mutant dinosaurs, and the Centre psychically attacked J'onn and took control of him. Faraday helped J'onn to resist the Centre's control and ultimately sacrificed his life in channeling the Centre's into his own boy, which killed him. Shocked of his friend's selfless sacrifice, J'onn changed into the Martian Manhunter and ferociously slaughtered the Centre's creatures swearing that Faraday didn't die in vain.
Following the Centre's destruction, J'onn joined the Justice League of America, and fought alongside with the heroes against Starro.
- Martian Physiology: The average Martian possesses the potential for the following power set:
- Shape-Shifting: Martians have psionic control of their physical for down to the molecular level. This allows them to a form of shape-shifting that allows them to mimic other forms, elongate aspects of their body, increase or decrease their physical size, and so on.
- Invisibility: Martians can cause the biopolymers in their bodies to lose their ability to reflect light, making the Martians invisible to normal light and human sight.
- Phasing: Martians can go through solid matter.
- Superhuman Durability
- Superhuman Strength
- Superhuman Stamina
- Extrasensory Input
- Super Hearing
- Martian Vision: Martian visual acuity greatly exceed human norms and allows for a wider range of information to be observed. This includes the following:
- Telepathy: Martians have the ability to read the minds of others and project their thoughts to varying degrees. They can also project their mental essences into a gestalt community known as the "Great Mind". Through this, the community can enhance the telepathic strength of other Martians. This power can also enable them to reverse the effects of amnesia or psychological brainwashing. 
- Astral Projection
- Mind Control: As an extension of this, Martians can also use the ability to alter a psychological profile of a target, enabling them to manipulate, and in some cases, outright control that individual. This practice is greatly discouraged however, and only rarely used. 
- Telepathic Relay
- Telepathic Assault
- Investigation: Highly developed detective skills.
- Personable Attitude
- Vulnerability to Fire: Martians are much more vulnerable to fire than the average Earth human. At times this has been portrayed as physical, psychological, or a combination of the two. The effect of this is to strip any Martian of their powers as they involuntarily lose control of their body.
- In the animated adaption of Justice League: The New Frontier, J'onn J'onzz was voiced by Miguel Ferrer.
- Appearances of J'onn J'onzz (Earth-21)
- Images featuring J'onn J'onzz (Earth-21)
- Quotations by or about J'onn J'onzz (Earth-21)
- Character Gallery: J'onn J'onzz (Earth-21)
- ↑ 1.0 1.1 1.2 1.3 DC: The New Frontier #4
- ↑ DC: The New Frontier #2
- ↑ DC: The New Frontier #3
- ↑ DC: The New Frontier #5
- ↑ DC: The New Frontier #6
- ↑ 6.0 6.1 6.2 6.3 6.4 Detective Comics #225
- ↑ 7.0 7.1 7.2 Martian Manhunter (Volume 2) #8
- ↑ DC Comics Encyclopedia: Updated and Expanded
- ↑ Who's Who: Update '88 #2
- ↑ 10.0 10.1 Martian Manhunter #4
- ↑ Detective Comics #226
|GCPD Officer |
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