An insatiable great white shark terrorizes the townspeople of Amity Island, The police chief, an oceanographer and a grizzled shark hunter seek to destroy the bloodthirsty beast.

Married small-time crooks Lou-Jean and Clovis Poplin lose their baby to the state of Texas and resolve to do whatever it takes to get him back. Lou-Jean gets Clovis out of jail, and the two steal their son from his foster home, in addition to taking a highway patrolman hostage. As a massive dragnet starts to pursue them across Texas, the couple become unlikely folk heroes and even start to bond with the captive policeman.

David, a college student, is looking for a job. He is hired by Dr. Stoner as a lab assistant for his research and experiments on snakes. David also begins to fall for Stoner’s young daughter, Kristina. However, the good doctor has secretly brewed up a serum that can transform any man into a King Cobra snake-and he plans to use it on David.