A geology expedition to the Amazon rain forest finds fossilized evidence of a creature from the Devonian Period with aspects of both and water animals. The leader, Doctor Carl Maia (Antonio Morena) visits a Brazilian Marine Biology Institute, where he runs into ichthyologist David Reed (Richard Carlson) from an aquarium in California. The latter persuades his boss to finance an expedition. Meanwhile, an amphibian humanoid is observing the expedition and the assistants left behind. They clash and the creature ends up killing them.
The expedition returns aboard the tramp steamer Rita under Captain Lucas (Nestor Paiva), including David, Carl, Mark (Richard Denning), David’s girlfriend Kay Lawrence (Julia Adams), and Doctor Edwin Thompson (Whit Bissell). They find the assistants dead when they arrive and think they were killed by a jaguar. For a while, they find nothing of note and they move on to the Black Lagoon, about which there are strange legends.
The creature is fascinated by the beautiful Kay and follows her underwater. It gets caught in the ship’s draglines and leaves behind a claw. Soon, more members of the expedition end up dead, until they capture the creature and lock it in a cage aboard the Rita. It escapes in the night and attacks Edwin. Kay hits it with a lantern, driving it away. When they try to leave, they find that the gill-man has blocked the lagoon’s entrance with logs. Mark is killed. The gill-man abducts Kay and takes her to its cave. She is rescued by the survivors and the creature is riddled with bullets. It sinks into the dark depths.
The film was produced by William Alland and directed by Jack Arnold, from a screenplay by Harry Essex and Arthur Ross, based on a story by Maurice Zimm. The gill-man was played by Ben Chapman on land and Ricou Browning under water, one in Florida and one in California. They met for the first time 20 years later at a convention. It was filmed in 3D, but the fad was dying and most people saw it in 2D. It spawned two sequels. Remakes were considered by John Landis, John Carpenter, Peter Jackson, Ivan Reitman, and Guillermo Del Toro, but nothing came of it. Julie Adams did all her own stunts.
Alland was told a story about a Mexican gill-man by cinematographer Gabriel Figueroa, and made notes for a story inspired by Beauty and the Beast. The creature was designed by Disney animator Millicent Patrick, but the credit went to makeup artist Bud Westmore. The bodysuit was designed by Jack Kevan, who worked on the Wizard of Oz and made prosthetics for World War II amputees. Chris Mueller made the head. Ben Chapman, who played the creature on land, could barely see in his mask, and Ricou Browning, who played it underwater, had to hold his breath for four minutes so as not to make bubbles. At one point, a snapping turtle bit off the rubber foot and he had to chase it down. Another time, he surfaced in front of a woman and child and they took off, screaming in terror.
Ingmar Bergman loved this film and watched it every year on his birthday. The costume was discarded by the studio and pulled out of the dumpster by a janitor to use as a Halloween costume for his son. Later, the parts were bought by superfan Forrest J. Ackerman and makeup artist Ben Westmore. Its design was based on 17th Century woodcuts of creatures called the Sea Monk and the Sea Bishop. A scientist named Jenny Clark, from Cambridge University, discovered a fossil amphibian in a swamp and called it Eucritta Melanolimnites, or creature from the black lagoon. During Marilyn Monroe’s famous billowing skirt scene in The Seven Year Itch, a poster behind her was advertising this film.