Somewhere in the Amazon rainforest, a grizzled trader known as Gringo the Damned (Whitman) leads an expedition into the heart of the rainforest in search of a legendary stash of jewels. Also seeking the treasure is an old Nazi (Pleasence) and his topless native wife (Sonia Infante), as well as a group of bungling young Americans. All must contend with alligators, killer crabs, bloodthirsty native tribesmen, corrupt customs officials, and each other's treachery.
Tropes:
- All Men Are Perverts: Zapata and Jairo are incapable of restraining themselves in the presence of Barbara.
- Argentina Is Nazi-Land: Von Blantz plans to transport the treasure to his Nazi comrades in Argentina.
- Bloodless Carnage: Definitely averted. With many deaths involving throat-slitting and decapitation, there is plenty of blood to be had.
- B-Movie: In common with most of Cardona's works.
- Creepy Child: At one point, Gringo's party encounters a pack of headhunting children.
- Death of the Hypotenuse: The low-key love rivalry between Clark and Dick is ended when the natives kill Dick, leaving Barbara to fly off with Clark at the end.
- Exact Words: When he gets caught trying to sneak his jewels out of the country Gringo points out that technically he had only denied finding gold; nobody asked about jewels. The official (who had previously executed von Blantz for the same thing) lets him live, implying it's out of respect for the sheer audacity of this argument.
- Fictional Country: At the start, a disclaimer makes it clear that the film takes place in a "fictitious place".
- Fingore: On the steamer, Gringo cuts off another passenger's finger with a throwing knife, then tosses the still-wriggling digit into the river.
- Godiva Hair: Marinba's long tresses cover up her breasts, at least most of the time.
- Greed: The fatal flaw of most of the characters.
- Hollywood Natives: The film is chock full of body-painted bow-wielding natives.
- Native Guide: Mostly averted in the case of Gringo's party, but Morinba serves as a guide and emissary for her husband Von Blantz.
- Ooh, Me Accent's Slipping: British actress Ann Sidney (Barbara) cannot maintain a Southern Belle accent to save her life.
- Only Known by Their Nickname: Gringo's real name is never revealed.
- Precision F-Strike: The first line of the movie is "Aw shit!"
- Scenery Porn: Of the Amazon, naturally.
- Southern Belle: Barbara is mostly played this way.
- Stupid Evil: Von Blantz kills his wife for no real reason, then gets himself killed trying to smuggle gold through customs.
- Those Wacky Nazis: Von Blantz is a former concentration camp official, and plans to use the treasure to finance a Neo-Nazi organization in Argentina.
- Tribal Face Paint: Most of the natives wear it.
- Troubled Backstory Flashback: We cut back briefly to the expedition where all of Gringo's friends were decapitated by headhunters.
- Wacky Cravings: On the riverboat, a guy is shown eating a tarantula for no particular reason.
