Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
There is a good snake scene in this but crocodiles play a much more important part in this popular action-adventure romantic comedy.
(You can see the crocodile scenes here.)
Joan Wilder (Kathleen Turner) is an introverted romance novelist with no romance in her life. She flies to Colombia to ransom her kidnapped sister Elaine with a treasure map that Elaine's husband sent Joan just before he was murdered. In Colombia, Joan becomes entangled in a dangerous romantic adventure with a handsome rogue named Jack Colton (Michael Douglas) as they hunt for a giant emerald.
In the snake scene, Joan and Jack are stranded in the jungle, as they are chased by a military man and his army. They find a wrecked airplane full of marijuana and dead drug smugglers. They go inside it to spend the night. Jack builds a fire and as the two talk, Joan becomes upset and tells him he's rude because he isn't looking at her when she's talking. But he's looking over her shoulder at a snake that's slowly crawling up next to her head. Jack quickly grabs his machete and kills the snake. She asks if it's poisonous. He says it is, it's a "bushmaster" and they're "very tasty." Later we see him eating a chunk of snake meat on a stick. They find their way to a town where they go dancing and hook up. That's the romancing part. The next day is the stone part.
They used a real snake when we see it crawl up into the air behind Joan's head. Then we see a fake snake that is killed and what might be a real but dead snake after he kills it. It's called a Bushmaster, but none of the snakes we see look anything like a Bushmaster.