In some cultures, a rabbit's foot is carried as an amulet believed to bring good luck. This belief is held by people in a great number of places around the world, including Europe, China, Africa, Australia, and North and South America. In variations of this superstition, the rabbit it came from must possess certain attributes, such as having been killed in a particular place, using a particular method, or by a person possessing particular attributes (e.g., by a cross-eyed man).

Source: Wikipedia