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 also had a university friend/acquaintance who claimed to be a werewolf. What’s strange is that he didn’t let everyone in on the secret. Just those close to him. He acted pretty normal 99% of the time, but when in the company of those who ‘knew’, he would sometime exhibit…well…werewolf behavior. No idea what happened to him.