Man-Bat

Man-Bat was originally a scientist named Kirk Langstrom who worked as a zoologist at the Gotham City Zoo. He experimented with bat mutagen to create a serum that would replicate their long life. After testing the serum on himself, he became Man-Bat. As Man-Bat, Langstrom exhibits characteristics of both man and bat. His strength vastly increases and he gains the ability to fly. When he was human, Langstrom was a scientist who focused on bats and specialized in genetic mutation, particularly DNA splicing.

Man-Bat first clashes with Batman when he tries to steal chemicals needed to reverse his transformation. However, his control over his new animalistic instincts resulting from his bat-like state is tenuous and Batman is forced to subdue him in order to administer the antidote.