Kirk Langstrom (Earth-4678)

"What are we gonna call this guy? Batman's already taken. I guess this guy is more of a Man-Bat anyway."

- Aaron Cash

Doctor Kirk Langstrom and his wife Francine Langstrom began working on a cure for his growing deafness using the DNA of a vampire bat. After injecting himself with the serum, Langstrom transformed into a monstruos man/bat hybrid the media later came to dub Man-Bat. Not being in control of his actions, the mutated doctor murdered his wife.

Source

 * https://dc.fandom.com/wiki/Kirk_Langstrom_(Arkhamverse)