Do you know who would be an interesting character for the Gotham TV show?  Dr. Kirk Langstrom, the alter ego of the Man-Bat!  No, not Batman, Man-Bat.  Dr. Kirk Langstrom, the Man-Bat, first appeared in Detective Comics #400 (June 1970).  Kirk was a scientist specializing in Chiropterology, the study of bats.  He develops an extract hoping to give humans a sonar sense similar to bats.  He hopes to cure deafness in this way since he himself was going deaf.  The extract works but also turns Kirk into a mindless man sized bat until Batman subdues and cures him.