Bill Clover is the owner of Clover Casket and Coffin, and lives in town on Mars. He is widely believed to be the quickest draw in town aside from Sparks Nevada and possibly Croach the Tracker. He also professes to be a coward at heart.
When the Barkeep, the current mayor of Mars, decided that Sparks Nevada needed to find a sheriff to keep the peace in town while he and Croach were off on other parts of Mars, the Mars-Earth Coalition agreed. The Barkeep came up with the plan to hold a quick-draw competition and invite several townsfolk to participate. One of the invitees was Bill Clover.
While all of the other attendees were incapacitated by Trigger Happy J.A.C.K., an automaton brought to test the quick-draw contestants, Clover found the courage inside of himself to overcome his cowardice and shoot J.A.C.K., saving the lives of everyone present at the competition.
Later, Bill enters the marshal station, upset at Sparks Nevada as he didn't know that winning the quick-draw competition would automatically promote him to sheriff on Mars. He insists to Sparks that he does not want to be the sheriff, but Sparks tells him he'll be a great sheriff. When a flying saucer lands outside, Clover, along with Sparks and Croach, greet the alien who lands. The alien calls him/herself Emperor Yessel. Sparks insists Bill tell Yessel to leave, else Bill will show Yessel why he's the sheriff on Mars with his quick-drawing. However, Yessel orders his/her robot, Gork, to shoot Bill. Bill panics and does not draw, and he is killed by Gork's bullet.