Children of Aya Moving
All stories come from something. The Piper is a lesser deamon known as a parasite that latches onto a larger deamon when it comes into the world. Then, once he is present he will follow that deamon (He tends to like to stick around Sorrow) to a town and call upon his minions. Rats swarm the town, consuming all food in the town, as well as weak flesh. Then once Sorrow takes hold of someone The Piper will slip into their body and move from town to town, consuming all in his path.