The Joker was created as a one-off and died in the same comic that marks his first appearance. His debut in 1940 painted him as a grimly tricky serial killer that frowned as frequently as he smiled. When the Batman confronts him, he lunges with a knife, staggers, and accidentally drives the blade into his own chest. With trademark hysteria he shrieks with laughter as he dies. But! Editor Whitney Ellsworth sensed potential in the Joker. He requested that a panel be added showing his revival in an ambulance, and for that we are grateful.
