I had a couple classmates that pretended to be vampires back in elementary and middle school. They’d pretend their Koolaid was blood, complain about the sunlight, and bite their friends a lot. Not enough to draw blood, though. I haven’t kept up with most of them, but one guy is a teacher now. He seems pretty normal.
I had a friend in primary school who, whenever challenged would go all raptor. Complete with a high pitched squawk and pretending to gut you with his claw. Then would walk away like nothing happened.