The Wild Hunt is an ancient folk myth that begun in Northern Europe. The Wild Hunt is a group of ghostlike creatures or dead men that roam the skies in prusiut of their prey. Varations of the story place heathen gods as the huntsmen. If you encounter the Wild hunt and help it you will be rewarded, if you do not you will be punished by the gods.
Seeing the Wild Hunt was thought to be a warning of oncoming war or catastrophe. If encountered you could be kidnapped and taken to the land of the dead.