Dr. Robert Kirkland "Kirk" Langstrom was a well-respected scientist who worked at the Gotham Natural History Museum, whose area of expertise was in the study of bats. Having fallen into a cave of bats as a child, Langstrom had always been fascinated by these animals, something that extended into his adult life. Once he began working as a zoologist, he created an extract from bat glands, made with the intention of giving humans the sonar sense of a bat, in the hopes it could help those were afflicted with deafness or blindness.
Unfortunately, Langstrom then makes the mistake of testing the formula on himself, mainly due to the fact that he had recently learned that he was also becoming deaf. Although the formula did work when it came to his hearing impairment, it came with quite a price, as Langstrom then gradually found himself transforming into a man sized bat/human hybrid, developing a bat like appearance, including giant wings. When he first met Batman, he treated the Man-Bat like another hero, after he helps him stop a gang of high tech thieves.
But this new friendship wouldn't last, as soon Man-Bat came into conflict with the Batman when he attempted to steal the chemicals needed to reverse his transformation from a local lab, but finds he has almost no control over his actions when in his Man-Bat persona. In fact, Batman is forced to bring him down and subdue him just so he can deliver the antidote to him, and restore him to normal. Batman manages to cure Langstrom of his affliction for a time, although Langstrom's fiance Francine also becomes afflicted with a similar condition, when Langstrom forces her to take the same formula, and she becomes the She-Bat. Batman manages to cure both of them, and Kirk and Francine soon become engaged.
Eventually, Langstrom manages to refine his serum, which allows him to maintain his human intelligence while in Man-Bat form, and also allows him to control his transformations. He attempts to work as a detective and Super-Hero for a time as Man-Bat, and he marries his fiance Francine, and they have a daughter named Rebecca. Nevertheless, he eventually loses control of the Man-Bat persona again, and stops being able to control the transformations, a situation which causes him to battle Batman several more times. Batman suggests that Kirk and Francine move to another city, and Man-Bat leaves for Chicago, and later, New York. He begins a detective partnership for a time with Jason Bard.
Post-CRISIS ON INFINITE EARTHS
After the events of 1985's CRISIS ON INFINITE EARTHS, Langstrom tries to maintain control of the Man-Bat persona and stay on the side of the good guys. He once even assisted Superman, when Jimmy Olsen inadvertently puts the Man of Steel inside a cave where Man-Bat was hiding out in, shunning the light. Man-Bat then offers to protect the Man of Steel from Kryptonite radiation that had reached Earth years after the destruction of Krypton.
Later, Kirk and Francine have a son named Aaron, but due to the alterations to both Kirk and Francine's DNA due to their nature as bat creatures, their own child is born with a bat-like appearance himself. Given the nickname "Baby Bat," Aaron was sought after by a team of criminals who wanted to use his powers to further their own ends. His whole family had to use the Man-Bat serum on themselves in order to defeat Aaron's kidnappers.
In the aftermath of 2005's INFINITE CRISIS, Kirk and his family attempt a normal life. But the international terrorist Talia al Ghul captures Francine Langstrom, and threatens to kill her if Kirk does not turn over the Man-Bat formula. In a desperate attempt to save his wife, Langstrom then gives Talia the formula, and she makes good on her word and releases Francine. Talia then uses the Man-Bat serum to turn certain members of the League of Assassins into her own personal army of Man-Bat style soldiers.
Some time later, during a time when Bruce Wayne was thought to be dead, several people attempt to assume the Batman role. During this time, Langstrom finds himself captured by the villainous Doctor Phosphorus, who reveals to him that despite what he's believed, the serum is no longer needed to begin the change into the Man-Bat. When Kirk finds out that Phosphorus has also captured his wife, he automatically transforms into Man-Bat to save her life.
However, Francine soon discovers that her husband's next transformation would be permanent if he did not take a newly created cure. Although Kirk attempts to take the cure, his Man-Bat personality won't allow him to do it. Right as Kirk is about to take the cure, Francine is wounded in the events of the Blackest Night, and an angry and distraught Langstrom transforms once again into Man-Bat, this time it seems for good.
Following the events of 2011's FLASHPOINT, almost all of Kirk Langstrom's history is reimagined. In this new incarnation, a villain known as Ignatius Ogilvy comes into possession of the Atavistic Gene Recall Serum, which was still created by Dr. Langstrom to help the disabled, and which he then unleashes upon Gotham City as an airborne virus. It then spreads throughout the city's 900 Block, creating an entire neighborhood of human bat creatures.
Langstrom reveals to Batman that he is the one responsible for the creation of the serum. Now feeling tremendous guilt over the misuse of his creation, he then uses a sample that Batman had procured, and he injected himself with it. By doing so, he creates an anti-virus that also becomes an airborne antidote, curing the afflicted. Although the citizens of Gotham are cured, Langstrom is now the sole Man-Bat creature in Gotham. As in the previous timeline, Langstrom's wife Francine later becomes a bat creature herself called the Bat-Queen, and even his father Abraham takes a version of the formula, becoming a Man-Bat as well.
Eventually, Man-Bat is recruited into the Secret Society during the Crime Syndicate's invasion of Earth. Langstrom is also employed by the secret counter terrorism taskforce called S.H.A.D.E., as well as becoming an instructor at the Gotham Academy, where he becomes the resident science teacher.