Perelesnyk
Perelesnyk (aka litavets). A figure in Ukrainian folk mythology and demonology akin to an incubus. He was believed to fly in the shape of a fiery dragon or young man, to enter homes through chimneys, doors, or windows, and to seduce women by assuming the appearance of a deceased spouse or lover. The perelesnyk has a female counterpart, perelesnytsia, but she rarely appears in Ukrainian folk mythology.