In the Alps, Saint Nicholas has an accomplice, a frightening creature called Krampus who punishes misbehaving children. Where Saint Nick’s sack is filled with goodies, Krampus uses his sack to carry off naughty children to his lair. The German-speaking world in fact has a number of traditions about a darker, more dangerous companion who is associated with Saint Nicholas. Between them, they pull off a kind of “good cop-bad cop” routine, with Saint Nicholas the kind and benevolent gift-giver and Krampus and his kin (Knecht Ruprecht, Zwarte Piet, etc.) as the threatening punisher of bad little boys and girls. So no matter who’s coming to town, you’d better watch out!
Krampus is a beast-like creature, although the particulars of his appearance vary from place to place. He has an assortment of animalistic traits including fangs, tusks, horns, and horsetails. There is an excellent article on the appearance and origins of Krampus at Atlas Obscura.
Krampus is the inspiration for the tradition of Krampuslauf or “Krampus run,” in which young men dress up as Krampusi (yes, that is the plural form) on December 5, the eve of the feast of Saint Nicholas, and roam the streets, frightening children. This evening is even called Krampusnacht or “Krampus night.”
Where did Krampus come from? He is clearly a holdover from pre-Christian Germanic traditions. With his bestial form, he bears a resemblance to woodwoses, satyrs, and other wild creatures of the forest. Although the church made efforts to discourage Krampus traditions, they persisted. By the seventeenth century, Krampus had become paired with Saint Nicholas and made part of Christmas celebrations of Austria, Bavaria, and other Alpine locales.
Krampus bears more than a passing resemblance to similar Alpine mythological creatures, most notably Perchten, another satyr-like being. (One is a Percht if masculine or a Perchta if feminine; more than one are Perchten.)
Perchten are the followers or attendants to Perchta (or Berchta or Bertha). This ancient Germanic goddess is a “guardian of the beasts.” In folklore, she is associated with spinning thread, an activity often associated in folklore with destiny or fate. In the summer, she blesses the flocks as the shepherds bring her wool. She oversees the spinning during the twelve days of Christmas, and is very particular about finishing the spinning on time. Any delay is said to bring misfortune on those who are responsible.
Perchta might appear as a stunningly beautiful woman dressed in white or as an old crone, what we might imagine as the traditional “Halloween witch.” Perchta is apparently the basis of the legends of La Befana in Italy and the “White Women” of Germany, the Netherlands, and France. Jakob Grimm thought her male counterpart was Berchtold, the leader of the Wild Hunt in sixteenth-century German folklore, but this may be simply a replacement for the feminine Perchta in earlier versions of the legend.
There are a number of beings similar to Krampus or Perchten in central and south-central Europe. These include the south German Quantembermann (“person of the four ember days”), the Slovenian kvaternik, and the Albanian bardha.