Mythical Creatures?

Djinn--A djinn is a spirit from Arabic mythology that can be either good অথবা evil. The djinn are less powerful than angels, but can assume the shapes of humans, জন্তু জানোয়ার অথবা whirlwinds. link They're also known as Genies.
Hell Hounds/Black Dogs/Devil Dogs--Basically সারমেয় from Hell. They can do the devil's bidding. Usually appear as black অথবা dark smoke. I guess they'd be bigger than most dogs. I'd be careful with these, because as it turns out a lot of people are scared when they see regular সারমেয় that are black, so I'd give them at least one unusual feature so that people are terrified of regular dogs. Maybe give them a symbol on the side অথবা make them transparent.
Werewolf(as opposed to just "wolf")--Well, নেকড়ে-মানুষ are cool... The beginning of werewolf lore described them আরো like shapeshifters. There's a cool wiki page about them, which shouldn't be too hard to find.
The Seven Deadly Sins--basically demons. Each one represents a different sin. Let's see if I can remember each one: Pride, Sloth, Lust, Greed, Envy, Gluttony, and Wrath.
Poltergeists--ghosts that are very powerful and torment people. They can সরানো objects and shake things and cause harm.
That's all I have right now. Just be sure to look up whatever আপনি use because they have origins that তারিখ back longer than Hollywood and can be very different from you'd expect. I'll post আরো if I think/find any more. Good luck!

There's a wendigo, a cannibalistic spirit. আপনি can গুগুল it for আরো info. There was an episode of "Fear Itself" with a wendigo, and it was the scariest thing I've ever seen.

Maybe a mermaid.