The Mask

No not the Jim Carrey Ritalin fever dream, but the 1961 movie of the same name that was the likely inspiration for the green faced hero.

When a patient kills himself after experiencing awful nightmares that bleed into reality, a psychiatrist receives a package from the dead man - a skull mask said to open the human mind like a rotten melon. Unable to resist, our leading man puts on the mask and descends into the madness of his own subconscious which contains freaky images of fire, masks, and ...hands? Yes, lots and lots of hand imagery. Then more fire, and then more hands, more than you can shake a ****** stick at.
originally shot with the nightmares in 3d, this psychological horror flick is actually really creepy and effective, while still proving plenty of riff-tastic moments to add to the fun. Check it out.