The Wild Hunt is a ritual which all Bosmer have the ability to perform. It permanently transforms all participants into mindless, blood-thirsty monsters who first consume all of their enemies and then themselves. The Bosmer have noted that all monsters in the world were born from previous Wild Hunts.
King Borgas of Winterhold in Skyrim was killed by a Wild Hunt in 1E 369. He fell victim to this whilst travelling to Cyrodiil in an effort to create a war against the Bosmer. This event was also the last confirmed wearing of the Jagged Crown until the 4th era.