Marvel Man hails from the world Terra, an Earth like planet that is light years away from Earth. The spitting image of Earth's Superman, his origins are similar but uniquely different. His society lived in an underground society on the planet Terra. This world was soon doomed when the caverns that housed their homes crumbled. His cousin (Marvel Maid's) father Jaal-Kor, wishing to spare his daughters life, sent her to the surface world in a drilling device. Arriving on the surface, she was found by a family who raised her in spite of the fact that she had super-human powers on Terra's surface. She soon became the super-hero Marvel Maid, that world's premier super-hero.
Marvel Man would share a similar fate being sent to the surface in another drill device but the device malfunctioned trapping him in suspended animation until he reached adulthood and was freed. Finding her long lost cousin, Marvel Maid decided she would someday need him as an ace in the hole against a super-villain and seeing that he needs a lot of time to learn how his new found powers work, she set him up with a civilian identity of his own: Ken Clark, a prisoner, who would secretly break out of jail when needed as Marvel Man. Marvel Man would operate in secret much like Supergirl of Earth would.
When Supergirl learned of the existence of Terra, she would go there with Superman's permission to ask Marvel Maid if she can take her place temporarily and see if she can prove to Superman that she can operate as a super hero and not make any mistakes. Marvel Maid agreed, however the subtle differences between Terra and Earth would trip up Supergirl who would in the end still manage to correct her mistakes and save the day. Marvel Man would come to her rescue, when her x-ray vision set an ice berg ablaze, and he would secretly try to assist her while she in turn trained him how to use his powers. He would almost be killed when Supergirl unknowingly turned coal into a diamond to distract a family from spotting them not knowing that it was the one weakness of Marvel Man.
After working together on numerous cases, Supergirl would later ask Might Maid to petition Superman on Earth to allow her to reveal her identity to her adopted planet given her performance on Terra. Marvel Man has not been seen since, his current fate following the many changes in reality caused by the Crisis on Infinite Earths, and other related disasters is currently unrevealed.
Presumably, Marvel Man has all the same abilities as the Earth-One Superman, although he is very unskilled in his abilities. At the very least he has been shown to have super-human strength, invulnerability, and the power of flight. It has not been revealed if he has other similar powers such as x-ray vision and super-breath. His only known weakness is to diamonds, which drain his power and can prove fatal in the same way Kryptonite is harmful to Kryptonians.
- This version of Marvel Man, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 2 Appearances of Ken Clark (Earth-One)
- 1 Images featuring Ken Clark (Earth-One)
- Quotations by or about Ken Clark (Earth-One)
- Character Gallery: Ken Clark (Earth-One)