A vampiric demon from Bulgaria, Poland, Russia, and Slovenia, a navi is created whenever a child dies before he is baptized or when a person drowns. It returns to the world looking like a common enough bird; it searches the countryside looking for its mother and calling out to anyone who will listen that it wants to be baptized. Never knowing its own mother’s love, it will attack women who are about to give birth, cutting them just deep enough to draw blood so it may take a drink. For seven years the navi can wander the earth calling out to others to help it. If it manages to persuade someone to baptize it, its spirit will be able to rest; if not, it will forever remain a demon.

Source: Georgieva, Bulgarian Mythology, 102-103; MacDermott, Bulgarian Folk Customs, 81; McClelland, Slayers and Their Vampires, 110