They came to him.
Every pernicious word uttered by a child lingered in the cavern, etching the name, date, and location on cold stone walls. Every new naughty child caused a hair to grow upon his lanky body. The more caustic the brat, the darker the hair. The crueler the crime the longer his horns. Whenever the whelps drew blood his nails grew, thicker and sharper.
He danced his talons along the balustrade and surveyed the workshop below. Thousands of tormentors, bullies, and unholy terrors labored over toys, games, and technologies they would never own. Oh how they toiled, their grimy malnourished little bodies bent and hunched. Not a word dared to be spoken, not a tune braved their misery.
Only when they'd truly repented would they be set free. He was in no rush to let them go. Good laborers took time to train. And patience. He had an abundance of one and none of the other. Plus, as the population expanded, so did the workshop. He was always shorthanded.
Lo, the holy days were finally here, when the children of the world faced the consequences of their words and deeds. Time to replenish the workforce.
He shouldered his bottomless bag and plucked a hair from his chin. The magic of the season opened a portal to the first of many new Entitled Little Vicious Evil Shits.
Tonight, he is coming to town.*
*Krampusnacht was last night, 12/5. Call it literary liberty.