Little is known about the early life of the man who goes by the name Doctor Moon. Indeed it is suspected that his title is unearned as no record of his accreditation can be found. "Genius can neither be confirmed or denied by a piece of paper" says Moon.
Indeed, Moon's skills as a surgeon cannot be questioned. Unfortunately, he has always put them to use on the wrong side of the law. "Law is nothing more than the weight of common opinion," he says. Moon has been hired to use his nefarious medical skills in one nefarious scheme after another. That these schemes constantly violate the Hippocratic oath does not seem to bother Moon. "Only a fool is bound by the words of one who is long dead", he says.
Over the years, Moon has travelled from job to job, usually operating in secret. He once reprogrammed a piece of catscan equipment in order to turn a reformed Catwoman back to her evil ways. He was also responsible for "brainwashing" Plastique in Belle Reve Prison for the Suicide Squad. He has been an employee of The Sunderland Corporation and an associate of the Captains of Industry; he has also overseen the metagene operation that changes Air Wave into Maser.
When asked why he does not use his obvious skills to heal the sick, Moon replies, "Healing is the body's natural process, and is therefore dull and commonplace. I am an experimenter - a pioneer, a misunderstood visionary." The Police of 6 continents would like to talk to Doctor Moon.
He also was with Phobia in the Injustice Gang Satellite. Merlyn has stated that when Dr. Moon and Phobia come to the satellite someone ends up missing.
Dr. Moon and Kate Spencer, as her Manhunter persona, get in a hand to hand combat situation and she stabs and kills him with his scalpel.
Justice League Unlimited
Doctor Moon appears in the Justice League Unlimited episode "Question Authority", but his voice actor is uncredited. He appears as a member of Project Cadmus replacing Hugo Strange, who could not be used because of the Bat-embargo. His task was to determine how much information the Question had read from the Cadmus files. Moon using a machine that makes the Question see what will happen if the Justice League went rogue like the Justice Lords. The Question resisted long enough to be rescued by Superman and the Huntress. Moon offered no resistance, but was still nearly killed by Huntress's crossbow, spared by Superman's intervention. He also makes cameo appearances in "Flashpoint".