J'onn J'onzz

J'onn J'onzz is the last surviving member of the Green Martians and hero Martian Manhunter

Biography
J'onn was born on Mars over one million years ago when it was a living world. He was a law enforcement officer with a wife, daughter, and twin brother Ma'alefa'ak who was a scientist. When Ma'alefa'ak mind-raped his wife, J'onn had him imprisoned. But his brother escaped and unleashed a plague that kills the planet's entire population. J'onn could do nothing as he watched his family die in front of him. Before the plague could infect him, he is suddenly transported through time and space to Earth by scientist Saul Erdel. The man dies of shock after seeing the Martian leaving J'onn stranded on Earth. After looking through some notes and books in Erdel's study he discovered his planet is dead and is the last member of his race. To blend in he goes by the identity of John Jones and becomes a detective in the Middleton Police Department.

Justice League
When alien vessels came to Earth seemingly peaceful, J'onn became suspicious of them. He started infiltrating the government to spy on the representatives who returned from the vessel. He discovered they were actually the White Martians who were thought to have been wiped out during a civil war. After confronting one, he is caught by the Justice League and decides to join them. They discover the Martians are planning to wipe out Earth's technology to render the planet defenseless by infiltrating the allowing them to conquer the planet. They manage to defeat the Martians by exposing their identities and save the Earth.

Powers and Abilities
Super Strength

Super Speed 

Flight 

Shape Shifting

Telepathy