J'onn J'onzz aka Martian Manhunter is a Martian from the planet Mars and is the last surviving member of his race. When his race engaged war with the White Martians, both civilizations were wiped out leaving J'onn alone. When astronauts landed on Mars and found J'onn he went with them and has since lived on earth and become a hero using the mantle of Martian Manhunter. He also shfits into a man under the name of John Jones when he takes a break and study's humans.