Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is mostly an adventure at sea movie with a romantic side story and dialogue out of a hard-boiled pulp fiction paperback. The great grandfather of Ricky, a secretary from Scranton, hid a million dollars in gold treasure 150 years ago on an island near Haiti. She goes to San Pedro where she hires a large sailboat to take her to Haiti to search for the treasure. (Why she doesn't just fly or sail out of Florida is never explained.) She hires Pete, a San Pedro harbor bum, played by Sonny Tufts, who knows the area where the treasure might be located to be her guide. It takes about two thirds of the movie to get to the Carribean island (which nobody ever call Serpent Island) and when they get there they spend at least 10 minutes showing us a bunch of chicken-sacrificing voodoo dancers who are protecting the island from treasure hunters. That leaves only a few minutes for the snake scene at the very end, but it's a classic of absurd action. When Ricky finally gets to a statue made of gold she sees a large snake which we're supposed to believe is guarding the treasure. She screams as the snake wraps itself around her. She wrestles with it for a while, sitting down, standing up, lying on the ground, until Pete grabs a machete and saves her. But he must not have killed the snake because it comes back to get rid of the greedy bad guy in the end.
I'm the kind of person who has bought a lot of books and records based on the cover alone and watched movies just because of the title, so I know the risks. This one had very little serpent action but I can't accuse it of false advertising. Plus I still enjoy the occasional reminder that they actually used to make movies as unbelievably bad as this one. MST3K has lampooned several films made by the director of this movie, but not this one, his first movie, so I guess it wasn't even good/bad enough for them.
It's a live snake that is being wrestled, but it doesn't seem to be putting up much of a fight. You can see somebody poke it with a stick in one shot and you can see that its mouth is tied up with what look like brown leather straps. I'm not sure what species the snake is - either a python or an unusually-patterned boa constrictor.
You can watch the terrifying battle with the giant snake on Youtube. If you dare!