As a tool to encourage good behavior in children, Santa serves as the carrot, and Krampus is the stick. Krampus is the evil demon anti-Santa, or maybe his evil twin. Krampus Night is celebrated on December 5th, the eve of St. Nicholas Day in Austria and other parts of Europe. People dress as Krampus and roam the streets looking for people (presumably, incorrigible children) to beat with a stick.
HELL. YES. Check this mo-fo out:
From Mental Floss.