Vyrkolak

This is a mythological character of Romanian mythology, a demon associated with eclipses of the luminaries, sometimes a werewolf or a vampire.

Vârcolac (rum. vârcolac) is a mythological character of Romanian mythology, a demon associated with eclipses of the luminaries. Other variants of the name: vîrcolac, vîrgolăc, vîrcolak, svîrcolak, zvîrcolac, vălcolak. The word is a fairly ancient borrowing from the Early Bulgarian vrkolak — "a werewolf, a vampire, a creature causing eclipses."

It was believed that they came from the souls of children who died unbaptized, from the souls of evil people cursed by God, as well as from the souls of some other deceased. They have the appearance of dogs or puppies, hunting dogs, wolves, often a snake. Their gaze has supernatural power. 

To drive away the Vyrkolaks, people had to make a loud noise. It was believed that they were afraid of people born on Saturday.