According to Wikipedia:
In German-speaking Alpine folklore, Krampus is a horned, anthropomorphic figure. According to traditional narratives around the figure, Krampus punishes children during the Christmas season who have misbehaved, in contrast with Saint Nicholas, who rewards well-behaved ones with gifts. Regions in the Austrian diaspora feature similar figures and, more widely, Krampus is one of a number of Companions of Saint Nicholas in regions of Europe. The origin of the figure is unclear; some folklorists and anthropologists have postulated a pre-Christian origin for the figure (see Germanic paganism).
Traditional parades in which young men dress as Krampus, such as the Krampuslauf (German 'Krampus run'), occur annually in some Alpine towns. Krampus is featured on holiday greeting cards called Krampuskarten.
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Krampus at Morzger Pass in Salzburg
Krampus parade in Pörtschach am Wörthersee (2013)