In New York, the ambitious Dr. Jack Byron and his associate Gordon Mitchell present the research of his assistant Sam Rogers to the CEO and board of directors of a corporation to sponsor a scientific expedition to Borneo. The objective is to find a flower, Blood Orchid, that flourishes for a couple of weeks every seven years and could be a fountain of youth, prolonging the expectation of life of human beings. They are succeeded and once in Borneo, they realize that it is the raining season and there is no boat available to navigate on the river. They pay US$ 50,000.00 to convince Captain Bill Johnson and his partner Tran to sail to the location. After an accident in a waterfall, the survivors realize that a pack of anacondas have gathered for mating and their nest is nearby the plantation of Blood Orchid, which made them bigger and bigger.

A “National Geographic” crew heads down the Amazon in a jungle boat to make a documentary on a long-lost tribe of natives. En route, they rescue a hunter from his sinking boat and take him on board. After the ship’s captain is attacked by a poisonous insect and goes comatose, the hunter commandeers the boat, takes the crew hostage, and drags them along on his insane quest to capture a giant anaconda.

A gang of jewel thieves board an empty luxury liner in the South Seas to find that the crew and passengers have been killed by a monster that kills its victims and sucks the water from their bodies that looks like a mix of a giant squid and the monster from “Aliens”.