Dubbed Frankenfish, the snakehead is a prized fish in Thailand that looks more like a snake than a fish. Snakeheads are ferocious predators, rumored to be able to walk on land, breathe air and attack humans. They've spread to the waters of the U.S., and fish biologist Dr. Zeb Hogan is on a mission to catch a monster snakehead. He starts off in Florida, which has come under attack by the invasive bullseye snakehead, one of the biggest of the species. Then, he travels to Thailand.