Most rabbits feet keychains are not actually made from a real rabbit's foot. Faux rabbit feet normally are covered with fake rabbit fur, and may be dyed in a variety of colors. To give the fake foot that dried bony feel, the internal structure is often made of latex. There are keychains made with real rabbit's feet available, though to be considered truly lucky, some believe the rabbit must be killed in very specific circumstances.
The superstition behind rabbit's feet keychains has roots in European cultures as well as hoodoo — a mixture of different American magical traditions. The reason why rabbits' feet are considered lucky also varies from the belief that rabbits embody spirits to the value placed in the rabbit's highly reproductive nature. To carry around a piece of a rabbit is believed to keep that luck with the carrier.
The full superstition regarding the luck of the rabbit's foot is quite complex. Not only must it be a real rabbit’s foot, but it must be the left hind foot, as it's considered luckier than the right hind foot. The luckiest feet are those taken from rabbits that are caught or killed in a cemetery. Even the times that the rabbit is killed may matter; some sources suggest that only a rabbit captured during a full moon, new moon or on Friday the 13th will have a lucky left hind foot. Some sources recommend cutting the foot off of the rabbit when it’s still alive, while others suggest that the rabbit must be killed by shooting it with a silver bullet, or killed by a cross-eyed person.
There are still many rabbit's foot keychains made from real rabbits' feet. They’re widely available on the Internet, in tourist shops, and sometimes casino vending machines. They’re often thought to be particularly lucky for gamblers, and are usually fairly cheap. As with any amulet, icon, or other lucky piece, the efficacy of the rabbit’s foot is highly questionable. A rabbit killed for the purpose of obtaining rabbit's foot keychains might want to argue that his feet were certainly not his fortune.