Greeks believed that a human could become a Vrykolakas after death by having lived an ungodly life, being buried on unconsecrated ground, being excommunicated or by having eaten the meat of a lamb that had been injured or killed by a wolf. Some Greek legends insinuate that even a werewolf could become one of the Vrykolkas upon it’s death. Individuals that had red hair and grey eyes were suspected of having been one of the undead, which I find intriguing as other ancient vampire lore states that any vampire with red hair was a direct descendant of Judas Escariot’s cursed blood line.