What/who is the scariest movie monster?

This is a follow up question to the Scariest Movie thread...

What would you say is the best movie monster you've ever seen? With regards to how it looks, and its background story...

They're all very good for different reasons, but...

I've always liked Frankenstein. You always felt sorry for him.

Werewolves, because they really don't have a choice about it. They can't control it, and it can really make life difficult for them.

My favorite however, isn't really a monster in the creature sense of the word, but someone that is kind of a monster in the things he does.

There was a two movie series with Vincent Price. The Abominable Dr. Phibes and Dr. Phibes Rises Again. Very campy with very weird and funny ways of doing in his victims. One of my favorites

I'm gonna say the H.R. Giger Alien from the Alien Quadrilogy.

With honorable mention going to the angel of death in The Mothman Prophecies

I GOT ONE...the creature or things you dont see in the Blair Witch Project...nobody knopws what it or they are...thats trippy enough

Pinhead the Cenobites from Hellraiser movies.

...no, I said 'scariest' ...not the 'coolest'