Some urban legends are created by adults who want to scare their kids into behaving. Anyone who grew up with Mexican parents will be well used to this method, and probably still feel a deep-seated fear of El Cucuy.
Other stories are more likely to have been made up by your jerk older brother who wants to freak you out. Such is the case of the Goatman of Beltsville, Maryland. Who is the Goatman? There is no official story, but most claim a scientist at the Beltsville Agricultural Research Center did experiments on goats. This somehow led to him actually becoming part goat, a kind of animal-human hybrid.
He is said to roam the backwoods of Fletchertown Road, attacking people and cars with his axe. Why a scientist-turned-goatman would carry an axe isn't explained.