In many ways, Martian Manhunter is like an amalgam of Superman and Batman. He is a detective, cunning and logical, but he is also one of the last of his race, capable of many of the same superhuman talents as the Man of Steel.
Science and science fiction have always speculated upon the notion that there was life on Mars. One scientist, Dr. Saul Erdel, attempt through experimental communication technology to contact the red planet. What returned through the beacon he transmitted was not just a message from Mars; it was a Martian, and not the sort fictionalized by H.G. Wells. This being was humanoid, at least to a degree, for his shape was random. He was a shape-shifter.
Erdel learned that Mars was dead, burned, lost in time. This Martian was named J'onn J'onzz. He had no desire to invade earth, but instead took to this world, joining its people and the Justice League to make certain that the end that befell Mars would never threaten Earth.
The Martian Manhunter's fear of fire suggest hypersensitivity, but this is too simple an explanation. His weaknesses would be too common to this world as well as Mars. Perhaps this is because his mass changes depending upon the form he adopts. 
- Martian Physiology
- Extrasensory Input
- Martian Vision
- Malleable Form
- Superhuman Speed
- Superhuman Endurance
- Superhuman Strength
- Investigation: Rivaling Batman, John Jones may yet been his world's greatest detective. Being connected to all other Martians makes hiding a secret a difficult task, John is trained to see the unseen and can detect a lie in more ways than just hearing your heartbeat. 
- Appearances of J'onn J'onzz (Justice)
- Images featuring J'onn J'onzz (Justice)
- Quotations by or about J'onn J'onzz (Justice)
- Character Gallery: J'onn J'onzz (Justice)
- ↑ Justice #3
- ↑ The powers and weaknesses listed are based on the common abilities of Martians first demonstrated by J'onn J'onzz. The refrences listed are based on J'onzz as depected in the Earth-One and New Earth continuities.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 Detective Comics #225
- ↑ Martian Manhunter #4
- ↑ Detective Comics #226
- ↑ Martian Manhunter (Volume 2) #8
- ↑ JLA #89
- ↑ Justice #3