regarding zombies/vampires, etc..
the first "known," recorded of such a thing occured in europe back in 1500 (if my memory is correct). what happened was a man died (unknown to the people that he was stil alive). after a quick funeral, that man was buried. later that night, the man woke up from his coma, feeling dazed and confused. he waalked back to his village, and the people (never seen anything like this) began to say it was the devil's work....they then killed the man again. only, this time, he is dead.
hmong and their stories are very similar. there have been stories of such a thing where the dead actually woke up from their funeral and live again normally. these are the more recent stories. however, hundreds of years ago, hmong had not the knowledge to detect a slow, beating heart. of course, hmong would say such a person is dead--simlar to the story in europe.
also, keep in mind, when mong does not understand something, they would also use dab as the cause. an old crazy person would be called dab if he/she acts differently from the norm. an animal would be called dab if it (as an example) has some kind of virus and acts strangely.
i am sure most of the mong stories are a result of things like this.
yh