The story of Knecht Ruprecht
The story of Knecht Ruprecht stretches back to the late Middle Ages. The legend is part of a centuries-old Christmas tradition in Germany, where Christmas celebrations start early in December.
Knecht Ruprecht is the dark companion of St. Nicholas, who rewards good children each year with gifts and candy on December 6, St. Nicholas Day. The hell-bound counterpart is known by many names across the continent, such as Knecht Ruprecht, Black Peter, Schmutzli, or also as Krampus. Knecht Ruprecht is usually seen as as a half-demon, half goat looking figure bearing devilish horns and a monstrous tongue, but he can also be spotted as a sinister man with a black beard bearing a black furry robe, a chain and bells along with a bundle of birch sticks to punish the naughty children. According to German tradition he appears in homes on St. Nicholas Day to ask parents about their children's behaviors. Depending on the response, he would give switches for use on the bad children, before dragging them into the woods.
Krampus, whose name is derived from the German word krampen, meaning claw, is celebrated on Krampusnacht, which takes place on the night before St. Nicholas’ Day. In South Germany, Austria, Northern Italy and other parts of Europe, party-goers dress up as the frighting looking Krampus creature bearing torches and stride through the streets terrifying children and adults alike. Krampusnacht is increasingly being celebrated in other parts of Europe such as Finland and France, as well as in many American cities.
(Sources: http://www.live-like-a-german.com/, http://www.krampus.com/, http://news.nationalgeographic.com/, http://www.toplessrobot.com/2011/12/10_fun_facts_about_krampus_the_christmas_demon_1.php)