No, but there are people with abilities that have SIMILAR characteristics such as a 'werewolf' and 'vampire'.
Shape shifting isn't actually possible. It's really the gathering of the energy to form shape and color visible to the human eye, but is hard to achieve. And the only physical shifting tends to be eye color, but its not like poof- suddenly have red eyes. :P
I would not say being a psychic vampire (or drainer) is something to not be proud of. I don't think we should be rude to someone for being born that way though :)
And for mermaids, it hasn't shown to exist.
Need any information? You can inbox me. But do me a favor, don't automatically believe everyone. I know you may be asking on here to see people's opinions too, but just believe in what ever you believe in. Just because someone says it, or someone post it online, or makes a website and says it, or even writes a book, doesn't make it true. theres ton of books on witchcraft and abilities that are fake. A lot of them actually are. (that doesn't mean they all are fake though)