 The causes of vampiric generation were many and varied in original folklore . In Slavic and Chinese traditions , any corpse that was jumped over by an animal , particularly a dog or a cat , was feared to become one of the undead . A body with a wound that had not been treated with boiling water was also at risk . In Russian folklore , vampires were said to have once been witches or people who had rebelled against the Russian Orthodox Church while they were alive . 
