Well I did some searching and this is what I find. Enjoy.
From the Kuriosita.com site...
http://www.kuriositas.com/2010/12/krampus-santa-claus-secret-weapon.html
But where did the legend of the Krampus originate? The word itself comes from ‘krampen’ and is from Old High German. It means claw.
Krampus is an incubus who accompanies Santa Claus, but does not follow the old man’s prerogative of present giving. An incubus is a demon in male form which visits sleepers and lies upon them (the word comes from the Latin ‘incubo’ which is to lie on top).
The Krampus is not your common or garden night rapist, however: his brief is to punish the children who have misbehaved during the year. In early twentieth century postcards, you can see the whip (or Virgacs) he would carry with him.
And further explanations...
There is high regional diversity – because of the isolation of alpine communities. In Bavarian traditions he is the “Wilde Mann” (nothing to do with Oscar, I can assure you!) and Knecht Rupert elsewhere but the tradition of punishment persists throughout. In the Hungary of the industrial revolution, the legend was softened somewhat. There he is seen as a mischief maker rather than evil and wears a black suit, with our contemporary idea of a suave but nevertheless silly devil fully to the fore. Here, he often carries a Virgacs, which is a set of twigs bound together, which children might get if they misbehave, but only as an accompaniment to their real presents!
And finally, for a modern day celebration...
The largest celebration is in the town of Schladming in Austria. Over a thousand Krampus gather. They carry sticks and light whips to punish those who have misbehaved often targeting, in particular, the young ladies of the town. Many of the young women of the town chose to stay at home on this night, the Germanic predilection for a good whipping being somewhat exaggerated! Some are brave enough to venture out, but they remain wary of any approaches by Krampus!
After seeing the pictures of these guys dressed as Krampus, I can't say I blame the ladies...