It was a goose that laid golden eggs wasn't it, and it was in Jack and The Beanstalk. I've found myself thinking a lot about that tale recently:
Would a modern Jack have sold his cow on eBay? Would he have taken Bitcoins for it, or are eBeans even better? What sort of person sells beans and would trade a handful for a cow? Did the bean-trader know they really were magic? Did one ill-judged deal drive Jack to a life of petty theft, stealing geese, harps and the like? I ended up terribly confused about the morality of the whole story, even though it ended happily for everyone except the giant.