I find Clown dolls very creepy.
My thing with mimes isn't scariness so much as it is downright hatred. I just don't like them at all.
When I was a kid, we were at the mall and some mime got a glimpse of me. And started waving at me with a big stupid grin, and I would kind of wave and shyly start to hide. (We were sitting down, and the mime was on the other side of the food court).
But I would hide behind dad, and that mime would get to an angle where it could see me, and wave, and that stupid grin...and waving! And I kept trying to hide...but the mime kept finding me!
I've hated them ever since.