Attempting to produce a serum that would allow blind people to replicate a bat's sonar, Dr. Robert Kirkland "Kirk" Langstrom tests the formula on himself. The serum mutates his genetic makeup and transforms him into the Man-Bat. Batman manages to capture the Man-Bat and administer an antidote. Taking inspiration from the hero, Man-Bat becomes a crimefighter but eventually gives it up to raise a family.