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 horror story about Harry Curtis (Raymond Elmendorf) a psycho-killer who murders dozens of innocent people at a cafe. That's not a spoiler, they show it to us at the very beginning so we understand how horrible the man we're watching really is. It's loosely based on the man who killed or injured 40 people at a McDonald's in southern California in 1984.
After Harry is released from a mental institution, his brother lets him stay in an abandoned hotel, which happens to be haunted with ghosts. Harry begins seeing ghosts and having hallucinations. I think the ghosts might actually be his hallucinations also, but that's not important.
In the first snake scene, we see Harry sleeping in bed at night. Then we see a snake slowly crawling through an open window down to the floor, across the floor, and up the bed where it crawls over Harry's foot and legs, up over the bulge in his tighty whities and over his torso until it stares him right in the face. Harry raises up and grabs the snake by the neck, but then he finds he is only holding the sheets. The snake was just another hallucination.
We see one more much shorter scene with snakes. A ghost hotel bellhop tells Harry about a haunted room where a woman jumped out of the window committing suicide and a man with a suitcase full of diamonds named Mr. Burns who later fell out of a window and died. Harry meets the ghost of Mr. Burns who tells him that a man comes to the room every day searching for the suitcase. He tells Harry that he can have the suitcase if he kills the other man. Harry finds the man and kills him, then Mr. Burns comes into the room and says "A bargain's a bargain. It's all yours." and sets down the suitcase then leaves. Harry opens the suitcase to find that instead of being full of diamonds, it's full of snakes. It's all just another hallucination.
The snake that crawls over Harry's junk is a live Boa Constrictor. The suitcase contains a variety of live snakes, including Kingsnakes, Milk Snakes, and Ratsnakes.