The word varcolac is a loan from Slavic (cf. Bulgarian varkolak, vulkodlak, Greek vrykolakas), meaning "werewolf" (etymologically "Wolf's Fur").

A varcolac in Romanian folklore may refer to several different figures. Some legends say it is a ghost or vampire (Strigoi) while others say it is a werewolf (in some versions, a werewolf that emerges from the corpses of babies. It can occasionally mean "goblin". Like the Norse Fenris, the varcolac can swallow the moon and the sun and is thus responsible for eclipses.

 In Latvian mythology, the Vilkacis was a person changed into a wolf-like monster, though the Vilkacis was occasionally beneficial.[citation needed] A closely related set of myths are the skin-walkers. These myths probably have a common base in Proto-Indo-European society, where the class of young, unwed warriors were apparently associated with wolves.

The pricolici is another form of varcolac, also resembling a werewolf.