80's Film Where Laughing Man Suffocates Victim With Plastic Mold

by Adrianne
(Toronto, Canada)

I saw this terrifying 80's movie when I was very young, but I can't remember the name.

A crazy, laughing man suffocates someone with a plastic mold (like a baking mold?), that has nipples painted on it. It's daylight during this scene, and I seem to remember it might have taken place in the desert.

I have been looking for years. If anyone can help, I'd appreciate it!