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".