Dr. Robert Kirkland "Kirk" Langstrom is a scientist specializing in splicing. He successfully spliced vampire bat DNA with human DNA, which he hoped to prevent and cure the human race of deafness. He tested it on himself, turning into a human-sized bat, known by many as Man-Bat.
Man-Bat was first seen in while Batman was on a mission to take on Scarecrow and the Arkham Knight. While ascending to the rooftops, Man-Bat came out of nowhere and almost struck the Dark Knight, only to miss and fly off into the night. Batman intercepts him and brings him down to Earth, only for Langstrom to ascend into the skies after he took a blood sample. Having found a DNA match for Langstrom, Batman headed for the laboratory he and his wife Francine were leasing in Chinatown.
Batman found the entire laboratory trashed and Francine Langstrom on the ground dead from blunt head trauma. It also showed Langstrom performing the experiment on himself before killing his wife and trashing the lab. Batman uses his computer to synthesize and antidote for Langstrom and pursues him, giving him the first injection. Langstrom escapes and isn't seen until later on in the game. Once he's seen again, Batman intercepts him once more to finish administering the antidote. Having been knocked unconscious by the antidote, Batman places Langstrom in the Batmobile and brings him to the GCPD, where he is reverted back to his normal self upon their arrival.
Kirk is placed in the isolation chamber Batman placed the recently released Poison Ivy and asked about Francine. When Batman gave him the unfortunate news of his wife's death, it seriously traumatized Kirk.
Somehow, later Kirk turns into the bat creature again and escapes GCPD.
If not, then he would face trial for murder, destruction of city property, and assault.
- In the comics, Kirk and Francine were both Man-Bat and She-Bat when they married. Langstrom in Arkham Knight however had married before becoming Man-Bat.