A man of modest beginnings, Joe Coyne earned pennies peddling newspapers, lost a job for pitching pennies in the office, and began a career in crime by robbing a cash register stuffed with pennies. Coyne learned to embrace the symbol of his failure, however, and he carved out a corner of the underworld by specializing in penny-themed crimes. He was eventually defeated by Batman, but to this day Batman keeps a gigantic penny in the Batcave as a souvenir of their battle.
DC Animated Universe
The giant penny was a staple backdrop piece in the Batcave in Batman: The Animated Series. The penny was once a deathrap tool utilized by Two-Face. On one adventure, Two-Face and the "Two-Ton Gang" captured Batman and tied him down to the giant penny. The penny rested on an over-sized coin-flipping machine. Two-Face boasted that if the coin landed on its bad side, then the Batman would be crushed, but even if it landed on its clean side, the impact would break every bone in Batman's body. Two-Face activated the flipping device and the penny sailed through the air. Fortunately, Batman had managed to pilfer Two-Face's lucky coin and used the jagged edges to cut through his ropes. The heavy penny instead landed on two of the villain's fleeing henchmen. 
- The Giant Penny is such a recognised part of the decor of the Batcave that variants on the theme can be found in similar bases: a Giant British Fivepence in the Knight's base, a Giant Wooden Penny in the Bat's Cave, and a giant false coin bearing the motto "In Stagg We Trust" in Batcave West.