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 bizarre and bloody British Sci-fi / Horror movie about monsters who suck the life out of people. No, not the I.R.S., these are some kind of non-human aliens who abduct and take possession of people, turning them into human meat puppets with psychic powers whose screams can make people's ears bleed. Sam is one of those monsters. After he is abducted we see a monster attack a woman. Then in a very disturbing scene, we see Sam being born from the woman's womb fully-grown. (Don't show this movie to any of your pregnant friends.) Three years later, Sam returns to his wife Rachel and his young son Tony with amnesia, unable to remember anything about the last three years. Spoiler alert: That's because he's really an alien monster who sucks the life out of people, and also likes to suck snake eggs.
Tony has a pet snake named Harry that we first see at the breakfast table. His mother Rachel tells him she doesn't want Harry in the kitchen so Tony should put the snake back in its tank. When Tony puts Harry back we see that there are four snake eggs in the tank.
Tony introduces Sam to Harry. Sam says Harry is beautiful. Tony tells him Harry laid four eggs.
Later we see Sam alone in Tony's room reaching into the tank and pulling out some snake eggs, then crushing them in his hand and eating the yolks. Tony looks into the room, sees Sam's egg-eating, gets upset and runs off. Sam follows him and explains that he's not the same as before they took him. He went to another world where he was changed so he could live there and now he has come back for Tony and Rachel. Tony tells him that he has the power to control inanimate objects with his mind. He has also been affected by the aliens, probably because Sam has been sucking on his skin.
Sam left the lid off of Harry's cage and Harry, like all snakes, has been waiting for the moment when he could escape. We see him leave the tank and crawl under the door. Later we see Harry crawl through a ceiling fan and drop down into the apartment downstairs.
Harry lands in a bowl full of salad greens. Mrs. Goodman, an anoying woman who lives there, pours dressing on the salad, then begins to toss the greens along with the snake. When she sees the snake she screams and drops it onto the table. Then she picks up a meat hammer that is conveniently laid right next to the salad and hammers poor Harry until he's a bloody mess with a tomato sauce.
Mrs. Goodman puts Harry's remains in a plastic bag and takes it upstairs to Rachel, telling her the snake showed up in her supper. Rachel asks how he got there, but Mrs. G just scolds her and says that it's ridiculous to keep a snake as a pet.
Tony is not happy that Harry has been turned into a baggie full of bloody salad topping and he wants revenge on Mrs. Goodman. Later that night he uses his psychic power to animate some of his toys and make them life-sized, including a life-sized scary clown and toy soldier with a rifle. The soldier breaks into Mrs. Goodman's apartment where it shoots at her then stabs her to death with his bayonet. Even if the kid is a soul-sucking murdering alien monster, you have to admire how much he loved his pet snake and feel good about Mrs. Snakehammer's violent end.
Harry looks like a live Garter Snake from North America, but since the movie was made in Great Britain, he might be a Grass Snake, one of the few species inhabiting the British Isles. I don't really know how variable they are in appearance. The animal wranglers probably used more than one snake to portray Harry, as well as a fake snake when it is tossed into the air, but whatever the live snakes they used are, apparently Harry is supposed to be a Grass Snake, since Garter Snakes don't lay eggs, but Grass Snakes do. Plenty of movies show someone eating a snake, but so far this is the only movie I know of that shows someone eating snake eggs, though I don't think the eggs we see in the movie are actually snake eggs. I'm guessing that the backstory for the snake is that Tony caught it and took it home where he named it Harry, only to find out that the snake was a female after she laid the eggs. That's a good example of why you should always think twice before taking a wild snake home. And don't forget to check your salad carefully before tossing it. You never know what might have dropped into it.