William Tockman was told by his doctor that he only had six months to live. Scared and desperate to take care of his terminally ill sister, Tockman decided to rob a bank. He was stopped by Green Arrow, and was in jail when his his sister died. When he found out that his doctor had mixed up his test results and he wasn't dying, Tockman becomes obsessed with timing and takes the identity of the Clock King. Even with precise timing, clock-themed capers and his stylish wardrobe, Clock King's plans have traditionally failed.