Diagnosed with a terminal medical condition with an estimated six months to live, William Tockman embarked on a crime spree to accumulate enough money to provide for his invalid sister's future under the assumption that a lengthy jail sentence was impossible given his prognosis. Believing that "time was running out" for him, Tockman adopted the clock, as his own symbol and used his extensive knowledge of clocks, watches and other timepieces in his criminal career as the Clock King.
The Clock King's time-related crimes initially came to the attention of Star City's crime fighters Green Arrow & Speedy. After a number of encounters, they finally defeated the Clock King and turned him over to the police. While awaiting trial, however, Tockman discovered that he wasn't dying after all; his doctor had accidentally switched Tockman's lab reports with those of another patient. Meanwhile, his invalid sister was placed in a state nursing home (Tockman's greatest fear), where she passed away.
Enraged by his sister's death, Tockman swore to get revenge against both his incompetent doctor and Green Arrow and he has escaped from prison several times over the years in order to do so.
Some time after his encounter with Green Arrow Clock King joined the Injustice League. After a few unsuccessful encounters with the Justice League International, Clock King along with other members of the Injustice League briefly reformed and became the core of the Justice League Antarctica. At some point after the disbanding of the JLI, they returned to their villainous ways.
While serving a lengthy prison sentence, the Clock King and a number of his former criminal associates are given a second chance as the Suicide Squad. The Suicide Squad is sent to a remote research facility to combat an experiment gone awry - a monster with a deadly explosive power. During the mission, many members of the Suicide Squad are seemingly killed - including Clock King - who was repeatedly shot while trying to escape. Clock King survives his brutal wounds, although Major Disaster believes himself to be the sole survivor. Cluemaster, who was shot in a similar manner to Clock King, also survived.
William Tockman has not been seen since, however, in an issue of 52, one character decides to kill all the time-travelers, and mentions someone "ending up like Time Commander and Clock Queen," possibly referring to Tockman.
Another Clock King appeared as the leader of the Terror Titans.
For more information see: Batman: The Dark Knight: Knight Terrors
Clock King is seen as one of several villain injected with Venom and Fear toxin, that makes them super strong and fearless. He is taken down by Birds of Prey.
Batman: The Animated Series
A professional efficiency expert, Temple Fugate was advised to deviate from his schedule for once in his life by future Gotham mayor, Hamilton Hill, only to have an unfortunate accident delay his arrival to an important court date and cause his financial ruin. Swearing revenge because he believed Hill had done it on purpose, Fugate returned years later, causing havoc and running afoul of the Batman.
Fugate, dubbed "The Clock King", used his knowledge of all-things time to evade capture, and returned years later with time controlling devices at his disposal in a plot to kill Hill. The Clock King was captured by Batman and Robin this time. He later returned in the guise of a butler and assistant named Harold to a reclusive scientist was studying time manipulation. This gave Fugate the opportunity to steal prototype time manipulation technology which allowed him to maneuver untouched in Gotham until Batman stopped him.
He was later enlisted by Task Force X for his organizational skills when they snuck into the Justice League Watchtower. Specifically, he designed much of the overall mechanics of the actual plan including the timetable of events, which included the compromise of some extra time allotted in the schedule to allow the agents some flexibility. In this role, he also acted as sort of a mission controller; providing status updates and guiding agents in the field in which he operated with his usual rigid efficiency. When last seen Fugate was still a member of Task Force X.
Batman: The Brave and the Bold
He appears as the first villain in the series facing Batman and Green Arrow. He tied up the heroes to their death in a pool with acid. The heroes managed to escape with the abilities of Green Arrow and Batman's utility belt. He tried to fight the heroes but failed miserably and got caught by police.
Batman: The Brave and the Bold: The Videogame
He appears as one of the mid-bosses in game in Episode Three. He fights against Batman and Hawkman as prelude to Gentleman Ghost.