Every year on December 5th Saint Nicholas returns to earth on his white horse and visits the homes of children leaving them gifts in their shoes that have been set out by the door.
When I was a little girl my father would tell us tales of St. Nicholas from when he was a little boy in Austria and of how St. Nicholas would visit their house in the evening and occasionally with him came the Krampus. A devil like beast with chains that would chase them around if they were found to have been bad until they promised that they would behave better from then on. Of course the chase was frightening but if they promised to be good they were rewarded with treats from St. Nicholas :)
Now the Krampus never visited us thank goodness but that definitely puts a new spin on the old 'you better watch out, you better be good' saying for old Santa Claus. If I knew the scary man with the chains was coming I would have been on my best behavior a lot more *grin*.