Utburds are actually really nasty.
In Scandinavia, back in the day, they practiced child exposure. That is, if there was one too many mouths to feed, one child (often the youngest) would be left out in the snow at night to die.
Sometimes, this would result in an Utburd, also called a Myling. Not quite a ghost, not quite a zombie, the Utburd would first take vengeance upon its mother. It would return to the place it once called home, and would enter through the keyhole like a wisp of smoke. Then, a cold, crawling, naked dead baby would crawl across the floor to the mother's bed. Despite its size, the weigth would be incredible. As it crawled up her body, her bones would crack and creak,and as it sat on her chest, it would reach up and take her eyes.
That wasn't the end, though. The Utburd would flee back into the cold, and haunt the night. Travelers would hear a mournful child's cry, maybe glimpse the small shape crawling through the undergrowth. But when not seen, the Utburd became big as a house. As the traveler walked, he would be followed by huge, thunderous footsteps. If he turned around, he would see nothing, though he might hear the cry of a baby. As soon as he begins to run, the footsteps resumed, merging into an unbroken roar of sound. When he tired, a great force from behind would pick him up, and flesh as cold and hard as glacial ice would crush him, snapping his limbs and twisting his body.
Imagine those stories of mothers who sometimes abandon their babies in trash cans or dumpsters. And now imagine the cold utburd, strong and big as a mountain, yet also as small and indistinct as a wisp of cloud, stalking the winter streets, looking for its mother, and then anybody else.