The land of Equestria is known for being protected by the princesses, whose power and influence goes beyond the limits known for common ponies. Their rule moves from the Crystal Empire to the Badlands and from one coast to the other one but, unbeknownst to anyone, there are places where their influence isn't so well asserted or well understood.
This places, close to Equestria's borders, are known for having little to no contact with the crown or its guard, they're also known for being extremely susceptible to fables and mysteries, since they lack the princesses's protection and guide, making them very susceptible to feeble legends of creatures whose origins are surrounded by myths and superstition. One of this myths is the legend of El Silbón, a creature who many say carries around the bones of his father and appears at the setting sun or morning dawns.
Under normal circumstances, this myth would be just put aside like the legend of Nightmare Moon and Discord but, as the saying goes:
"If the river sounds, it's because its bringing stones".
Story inspired on the Venezuelan ghost story of El Silbón/The Whisperer for Halloween. While this is my first attempt at writing a ghost story, I do hope that I manage to get some of you a good scare.
P.S.: The saying means that if there's a rumor, it's because something must have originated it.
P.S.S: Since there's no way to find a ponyfied version of El Silbón, I'll use a picture of him instead.