I'm looking for the title of this movie I watched years ago set in modern times where the hero comes across this society of monsters (mutated people with strange powers) living underground in secret. If i remember correctly the entrance to their place was in a cemetery, possibly in a tomb. In any case the hero finds out he is really of of them and ends up helping them fights off humans come to kill them. In fact at some point I think a little girl was abducted and taken to the local police station where the hero had to rescue her before something happened (she was going to change shape/die/something). I think she was named Babette.
It's an 80s or 90s movie. I also have this impression it was also a book.
Anyone have any ideas?