What horror character to write about?

I'll read your vampire story any time you want me to, just be careful not to ever give all your work to any one person. Many people would want to steal your ideas, so i repeat always be cautious with who you give your stories to. Maybe just give them a chapter or two so that they can't steal too much. As for the new character i'd go for the craziest type of villain you can come up with. Think about it, The Joker in The Dar Knight, Voldemort in Harry Potter, Hannibal Lecter in the Silence of the lamps, Darth Vader in Star Wars, the Dark Lord Sauron in the Lord of the Rings, The White Witch in the Chronicles of Narnia. The best stories always have amazing villains that are almost unforgettable. That's my advice to you, I hope i helped.