Man-Bat was the second ongoing comic series featuring a Batman villain, the first one being Joker (Volume 1). Man-Bat started publication in 1975, but was prematurely cancelled after the second issue by DC Comics Publisher, Carmine Infantino. The Man-Bat stories featured in this series were later moved as back-up features on Detective Comics (Volume 1) and later Batman Family (Volume 1).
EHT Comics 