Bill Finger (1914 to 1974) co-created Batman with Bob Kane in 1939. He designed the cape, cowl, and overall visual identity of the character and wrote many of the earliest Batman stories.
Finger contributed to the creation of Robin, the Joker, Catwoman, the Riddler, and the Penguin. He also co-created the original Green Lantern (Alan Scott) and Wildcat. His contributions went uncredited for decades until a formal acknowledgment began appearing in 2015.