Pazuzu - Eileen Dietz
The crew for The Exorcist called up Eileen Dietz to see if she could take on the role of the devil, Pazuzu. Although she wasn't actually the King of Hell, they superimposed her face onto the devil's to create a super eerie, nonhuman face. This moment, along with many others from the film, has stayed with people their entire lives.
Pennywise- Tim Curry
In the original It, Tim Curry put on the clown makeup and got to work. He wore a special headpiece to give his head an enlarged shape, but the rest was simply makeup. It's hard to compare the new-age Pennywise to the old one since they're so different and scary in their own unique ways!