Page "Werewolf" Paragraph 44

According to the first dictionary of modern Serbian language ( published by Vuk Stefanović-Karadžić in 1818 ) vukodlak / вукодлак ( werewolf ) and vampir / вампир ( vampire ) are synonyms, meaning a man who returns from his grave for purposes of fornicating with his widow.

The dictionary states this to be a common folk tale.