The Chopper Patty is a burger featured only in the episode "Born to be Wild" to promote The Wild Ones.
The burger has the usual toppings, with the tomato and lettuce, as seen on any other Krabby Patty, but the burger meat is shaped like a bicycle/motorcycle in order to attract the Wild Ones Bikers.
Role in episode
Mr. Krabs brought the Chopper Patty to the Krusty Krab when he heard that the Wild Ones were in town. He thought bringing in perks like the Chopper Patty would get the Wild Ones into the Krusty Krab.