Strigloi

Certain people commit deeds so vile that they live on in tales meant to frighten children. Repeated by enough parents over enough years, the tales gather substance among the spirits until at last they break through to the Prime Material Plane as something far worse than a bogeyman. These spirits, the strigloi, hunger for more than fear: like the horrors of the stories, they devour children's blood and flesh. They creep into homes in the small hours to steal children, and no child taken is ever seen again.

A strigloi looks like an impossibly old man or woman, wrinkled and pale, with limp hair and a coat of fine dust. To fly, it merely springs upward and then either turns invisible or appears as a glittering white light or flame.

It will flee any adult if it possibly can, since it hunts only the young and saves its effort for them. Two successful hits let it carry a child away. It has never been seen to use its poisonous bite on the child it means to steal, reserving it for anyone defending the victim. It may also paralyze a defender, carry him high into the air, and let him fall.

Nonmagical weapons deal only half damage, and the spirit's foulness corrodes any such weapon that touches it, rusting or rotting it at once so that it breaks on the next swing.

As a shamanic spirit, a strigloi accepts any evil alignment. It will deal with any shaman who proves power over it, for example by briefly binding it with contain spirit. No good-aligned shaman would ever want a bargain with such a creature, of course, and should try to destroy it instead.

For each spell it sponsors, it expects a weekly pint of fresh blood drawn from an intelligent creature, simply handed to its physical form with no formal sacrifice. Pints given ahead of time count as credit. It does not want worship. The spells it sponsors are haunting notes, death candle, and contain spirit, and it is whispered that a favored shaman may also gain the wizard spell vampiric touch, usable two times daily. What vile rites earn that gift is known only to the blackest-hearted spiritualists.