While searching for oil in the deadly swamplands of the Florida Everglades, members of a geological expedition meet an insane doctor who is working on an experiment to create a creature that is part man and part alligator.

Deep in the rural swamps of Texas the mad Dr. Simond Trent is conducting experiments on the local swamp people in an attempt to discover the secret of evolution. When a party of oil surveyors comes upon his isolated laboratory he decides to take the final step and turn one of them into a grotesque amphibious creature.—Jeremy Lunt <[email protected]>

Deep in the rural swamps of the South, the reclusive mad scientist Dr. Simond Trent is trying to discover the secret to reversing evolution. HIs test subjects are the local, impoverished blacks. Each failure is thrown into a covered swimming pool full of alligators. For his last try, he used his lab assistant Tom. A member of an oil exploration team arrives in the area, staying at the Fly'n Fish Hotel. In the bar he reveals his company's confidence that there is a rich oil deposit waiting to be discovered in the area. The unethical hotel staff try to steal information of the oil's suspected location but are caught in the act. The ensuing tussle leads to the oil man's death. His body is disposed of in the swamp. Knowing that a second oil explorer is coming, Brenda Simmons, the female bookkeeper for the hotel, decides to masquerade as the dead man's wife. That way, they will be led to the potential well site by the new man, Barry Rogers. Barry, Brenda, hotel employee Ritchie and guide Rabbit head out and eventually encounter Trent's home and lab. Trent's wife Pat is desperate to convince Barry that her husband has grown insane in his experimental obsession. Simond locks her up, telling the house-guests that has serious health issues. Thinking he has finally got the perfect formula, he sneaks up on Brenda as she is sleeping and injects her with an anesthetic mixture that knocks her out. He then takes he to the lab where he transforms her into a grotesque and virtually indestructible amphibious "Fish Human" so that he can take his mark upon the world.—Garon Smith