well it all truely depence on ones mind seat to answer this question
Vampires do exist and they should not be glorified.
It's possible, but not naturally
Yes, the devil made them to kill the holy.
Unless you count kids that drink blood for fun, nope.
I'll believe in them when I see one, but unfortunately I probably won't have much time to spread the news.
Yes they totally exist along with the talking robot monkey in my closet.