J'onn J'onzz is one of the last living green martians.
He was stranded on Earth. Though he had never done anything wrong, J'onn found himself on the run from the Department of Extranormal Operations and their leader, Hank Henshaw. Henshaw had grown obsessed with capturing every alien he discovered, innocent or guilty. Cornered, J'onn was saved by DEO agent Jeremiah Danvers, who gave his life to stop Henshaw. Jeremiah's dying request was for J'onn to look after his daughters, which J'onn fulfilled by shifting into a double of Henshaw and psychically copying his personality to become the head of the DEO.
- 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
- Density Control: A secondary effect of shape-shifting is the ability to make his body phase through objects like a ghost.
- Multilingualism: J'onn can speak his native Martian and English. Presumably, he can learn language through telepathy.
- Hand-to-Hand Combat (Advanced)
- Military Protocol
- 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.
- This version of the character is exclusive to the continuity of the television series Supergirl, its tie-in comic book series, and its related television series. It is an adaptation of J'onn J'onzz. The original character was created by Joe Samachson and Joe Certa and first appeared in Detective Comics #255.
- J'onn J'onzz/Hank Henshaw is portrayed by David Harewood. Throughout the series, the character has defaulted to using the appearance of Henshaw. This is due to the story elements of him attempting to blend in and the cost of the CGI used for the character's Martian form.
- J'onn was born ca. 1699.
- Appearances of J'onn J'onzz (Arrowverse: Earth-38)
- Images featuring J'onn J'onzz (Arrowverse: Earth-38)
- Quotations by or about J'onn J'onzz (Arrowverse: Earth-38)
- Character Gallery: J'onn J'onzz (Arrowverse: Earth-38)
- ↑ Revealed in "Human for a Day"
- ↑ "Childish Things"
- ↑ For the first time in "Blood Bonds"
- ↑ "Changing"
- ↑ "Exodus"
- ↑ "Midvale"
- ↑ "In Search of Lost Time"
- ↑ "Dark Side of the Moon"
- ↑ 9.0 9.1 9.2 "Strange Visitor From Another Planet"
- ↑ 10.0 10.1 "Human for a Day"
- ↑ 11.0 11.1 11.2 11.3 11.4 Detective Comics #225
- ↑ 12.0 12.1 12.2 Martian Manhunter (Volume 2) #8
- ↑ DC Comics Encyclopedia: Updated and Expanded
- ↑ Who's Who: Update '88 #2
- ↑ 15.0 15.1 Martian Manhunter #4
- ↑ Detective Comics #226
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