J’onn J’onzz (popularly known as the Martian Manhunter) is a native of the planet Mars and a green Martian by race. Accidentally teleported to the planet Earth by a human scientist, he was unable to return to his home planet through the portal that brought him to earth. Thus, he used his powers to fit in, adopting a human-like appearance and calling himself “John Jones”. He joined the police force and secretly used his alien powers to help the inhabitants of his new home planet.
John possessed most of Superman’s powers, as well as added abilities like invisibilty, telepathy and the ability to control his molecular structure, which enabled him to shape-shift. His only weakness was towards fire, which affected him in much the way kryptonite affected Superman.
A founding member of the JLA, Martian Manhunter has been a key member of the League since its founding. Telepathically linking the Leaguers during combat, John plays a pivotal role in the League’s functioning. Furthermore, his immense strength and durability makes him one of the team’s foremost powerhouses, along with Superman.
The death of his entire race, has caused Jones to choose to remain on his adopted planet. It was later revealed that his race’s sworn enemies, the White Martians, have survived and their plans of conquest of Earth have brought them into conflict with the JLA several times. The White Martians consider Jones to be a traitor for opposing them, and as such have captured and tortured him.
Superman and the Martian Manhunter have much in common. Both are super powerful aliens who have come to adopt Earth as their planet. Both are good hearted people who fight for truth and justice and wouldn’t hesitate to lay down their lives to save others. However, where Superman is loved and admired by the public, Jones is shunned and feared, primarily due to his alien appearance. Jones is well aware of this and tends to avoid exposing himself to humans, except in the guise of police detective John Jones. His complex is deep rooted and though he bears no malice or ill-will towards Superman, on more than one occassion, he has asked himself, why people love Superman and not him. This changes when, after saving the world yet again, for the first time ever, a small kid comes up to him and hugs him, thanking him for saving the world.