A horror film featuring nature running amok in the form of mutated beasts, carnivorous insects, and normally harmless animals or plants turned into cold-blooded killers. The cause of these mutations is almost invariably man, who through scientific carelessness or a lack of environmental concern will release something (nuclear waste, toxic chemicals, untested formulae) into the natural world with deadly results (Kingdom Of The Spiders, Food Of The Gods, Day of The Animals, Piranha, The Creature From The Black Lagoon). Beneath the thrills there lurks cautionary commentary on man's treatment of nature and a growing concern that environmental neglect will come back to haunt the existence of mankind. Sometimes, it is anger and vengeance that fuels these creatures (Frogs, The Birds, Orca) or just a plain bad temperament (Grizzly, Cujo). While it was not uncommon to see movies exploiting nature's predators before 1975, it was the success of Jaws that spawned many of the subgenre's works, as studios rushed out their competing version on the nature-taking-revenge theme.