Trying to remember a book series i read as a kid?

Ok, if someone can remember this, I will be very impressed. It was a series of books for teens or young adults. I think it was about a school that had some normal kids in it, but it also had a young vampire, a young frankenstein, a mummy, a werewolf, and maybe some other of those type creatures. They all went to school together. I don't remember the name of the series obviously, but I remember it might have included the name of the school and I DO remember that the name of the school was PS and a number, PS I guess standing for private school, followed by the school's number. Any help or am i crazy?