Roh Kar was a Martian lawman who traveled to Earth to apprehend a Martian criminal, who had fled the planet after stealing an invisibility belt. Soon after his own arrival on Earth, Roh Kar met the Batman and Robin. Already familiar with the Caped Crusader's reputation as a lawman on Earth, from the observations he and his fellow Martians had made of the people of Earth in general and the Batman in particular, Roh Kar gladly accepted the Dynamic Duo's help in pursuing and capturing the alien criminal.
- Oxygen: Earth's atmosphere and the oxygen present in it, made Roh "dizzy". This problem was easily controlled by breathing lightly.
- This version of Roh Kar, 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.
- This character was introduced as "The Manhunter from Mars", which probably served as the inspiration for the Martian Manhunter introduced two years later, or maybe it was just a true coincidence.
- 1 Appearances of Roh Kar (Earth-Two)
- 1 Images featuring Roh Kar (Earth-Two)
- Quotations by or about Roh Kar (Earth-Two)
- Character Gallery: Roh Kar (Earth-Two)