Frankenfish is a 2004 American monster movie dealing with genetically engineered fish in the bayou. The film was based on the snakehead fish incident in a Crofton, Maryland, pond. It is one of three movies based on the incident, the others being Snakehead Terror and Swarm of the Snakehead.

Sam and Mary find the boat along the bank of a canal. They explore the interior while Elmer waits in the canoe outside. They discover the remains of the crew in the hold. Upset, Mary clumsily knocks Elmer from the canoe and something drags him down. Sam and Mary flee in the canoe, unaware that they have triggered a homing signal on the ship. On the mainland a team relays the information to their employer a wealthy bounty hunter.One of the villagers heard noises while on his porch. He leans over the edge and a frankenfish leaps up and decapitates him. His girlfriend attempts to escape the houseboat on a canoe but the fish flips her out and kills her. Frightened, the group tries to flee in boats but the fish destroys them. On a neighboring stilt house, Ricardo baits a large hook using an entire catfish and manages to land one of the frankenfish. Nearly as big as a fullgrown man, the fish can breathe air and hops forward biting at Ricardos legs. Ricardo manages to kill it with a shotgun blast to the head. In vengeance he tears out its heart and barbecues it. As he takes his first bite a second frankenfish leaps from the water and devours him. ........

Source: Wikipedia