I just ran across a reference to the Rabbit's Foot loot drop in-game, saying that many people always carry one of these. As far as I know, they only drop from wolves, and maybe rabbits, but since I don't go killing rabbits, I'd not know.
But here's the thing. It wasnt' lucky for the rabbit. And it wasn't lucky for the wolf. So why do you think it could possibly be lucky for you?
We live in a land of living gods and demons, who bestow their powers directly upon us, and yet people insist on making up superstitions?