One of the last survivors of the civil war that ravaged his home planet of Mars, J'onn J'onnz traveled to Earth and now fights to protect his adoptive home. J’onn J’onzz of the planet Mars was accidentally transported to Earth, where he became one of its greatest champions under the moniker Martian Manhunter.

He used his shape-shifting ability to assume the alias of John Jones, a hard-boiled detective working out of Middletown, Colorado. Eventually J’onzz changed his heroic name to the Martian Manhunter, after the term often used to describe police officers.