By the Gods!

The creepy hand in THE TEN COMMANDMENTS (1956) 

It's funny that one of the best horror scenes ever put on screen is not even from a horror movie. The creepy green hand in the sky is amazingly effective and very Halloween. The plague of the First Born is set into motion and God's hand (?) slowly takes shape in the sky. Only by painting lamb's blood over a doorway can stop the creepy hand from killing any first borns inside a house. DeMille at his best.