Barney Kirkwood, AKA the Butcher of Ballad was a serial killer who nearly escaped persecution as the bodies were never found. He apparently fed his victims to his dogs, which inspired the Devil to punish him by having hellhounds attack him for all eternity, which in-turn caused him to become a dog monster when he returned from Hell, it also made him sensitive to dogs, Spike in particular. In the end Sam stabbed him with the vessel, a meat thermometer.