Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a schlocky supernatural horror movie with a cast of well-known actors who must have needed the money. It's about a cult of Satanists who can use magic to melt people and it has a brief scene with a snake conjured with magic.
Jonathan Corbis (Ernest Borgnine) is the Satanist cult leader. Mark Preston (William Shatner) and his family are hiding an ancient book with the names of people who sold their souls to Satan which Corbis needs to deliver them to Satan along with their souls which he has trapped in a vessel called the Devil's rain. (Why does Satan need to bother with rules? It must be because he's the monster who invented red tape and excessive bureaucracy.) Corbis lost the book when he was burned alive 300 years ago by Christians, swearing that he'd come back to kill all of Preston's ancestors.
Preston's mother (Ida Lupino) gives him an amulet and tells him that Corbis can't harm him as long as he is wearing it. Preston puts the amulet around his neck and goes to meet Corbis. Corbis demands the book but Preston refuses to give it up. He holds up his magic amulet at Corbis. Corbis says "Behold!" and the amulet turns into a snake coiled around Preston's neck. Preston freaks out then pulls off the snake and throws it to the ground where it immediately turns back into the amulet. Preston rushes over to grab the amulet but Corbis steps on it and captures Preston, who is no longer protected.
Later when Preston is being offered up as a sacrifice to Satan, his face is changed into an eye-less mask that is essentially the same mask "Captain Kirk" mask worn by slasher Michael Meyers in the Halloween movies before it was painted white.
The snake is a juvenile Boa Constrictor. When we see the snake we hear the absurdly loud rattling sounds that we usually hear in a movie whenever a snake appears.
You can read a synopsis of it and watch the whole movie at the SilverScream.com.