The aquatic member of the Justice-9 from Earth-36.
Mer-man was created by Grant Morrison and Evan Shaner. His first appearance was in The Multiversity Guidebook #1.
Mer-man is based on the Atomic Sub, the Big Bang Comics analogue of Aquaman. He was a briliant scientist who discovered a special chemical formula fro a synthetic blood that allowed for underwater adaptation and after an accident, his mind was placed inside a near indestructible cyborg body, fueled by the formula.
The Multiversity Guidebook
Mer-Man appears in this issue as member of Justice-9, the Earth-36 analogue of Round Table of America (which is in turn based on Justice League of America). Earth-36 is an analogue of the Big Bang Comics Earth.
Powers & Abilities
Not all of Mer-man's powers have been revealed, but they resemble Aquaman's and the Atomic Sub's powers.
Mer-man possesses superhuman strength.
Mer-man possesses a cyborg body with superhuman durability.
Superhuman Swimming Speed
Mer-man can swim at superhuman speeds.
Mer-man possesses superhuman sight, due to his cyborg body.
He can function normally underwater and is able to withstand the high pressures and extreme temperatures of the deep. He can also function on land normally.
He can fly at high speeds, with the aid of his cyborg modifications.
He has the ability to track objects underwater with the sonar in his hands.
He is long lived and his cyborg body doesn't age.
He is a genius scientist that worked against the Nazis, and has created a number of scientific marvels, like his cyborg body and synthetic blood.
Weapons and Equipment
He wears a distinct helmet that only exposes the front of his face, similar to the Atomic Sub.