Örümcek fobisi olan Dr. Ross Jennings (Jeff Daniels), başka bir kasabaya taşındığında bu korkunun tüm kasabayı tehdit ettiğini görür. Venezuela'dan yolculuk yapan öldürücü bir erkek örümcek kasabanın ziyaretçisidir.

Genetik olarak değişime uğramış ve eskisinden çok daha büyük bir hal almış olan Anaconda, bu yepyeni aksiyon ve korku yüklü versiyonu ile karşınızda. Ölmek üzere olan önemli bir iş adamı (Emmy Ödülü adayı John Rhys Davies) bir doktorla anlaşır ve lanetli orkideleri korumak için laboratuvar ortamında bebek bir yılan yetiştirir. Bir gece aniden büyüyen yılan önüne çıkan her şeyi yok eder ve güzel virüsbilimci Amanda (Crystal Allen) onu durdurmak için her şeyini ortaya koyar.

Africa in the sixties. The Nile perch, a ravenous predator, is introduced into Lake Victoria as a scientific experiment, causing the extinction of many native species. Its meat is exported everywhere in exchange for weapons, creating a globalized evil alliance on the lake shores. An infernal nightmare in the real world that wipes out Darwin's Theory of Evolution.

In 1890, one man had the idea to collect every bird ever mentioned in Shakespeare and release them into Central Park. The only bird to survive in the New World was the European starling, which became one of the most common birds in North America. Its introduction is now widely considered a major environmental disaster.

In 1940 twenty Canadian Beavers were brought to 'Tierra del Fuego' island in southern Patagonia for commercial fur production. However, beavers having no natural predators, quickly spread throughout the island, causing massive destruction of trees threatening the entire Patagonian forests rivers and species. Why wildlife conservationist are convinced that 150.000 beavers must be killed? Why some of the most recognized specialist are convinced that an eradication is not possible? Meanwhile truism is capitalizing on the situation: a man dressed as a beaver passes out flyers promoting a famous sky resort: 'Cerro Castor' - Beaver Hill. Hunters claim for subsidies, scientists are researching, rangers do what they can and restaurants tray to offer beaver meat to tourist.

After decades of hurricanes and oil spills, Louisiana faces a new threat - hordes of monstrous 20 pound swamp rats. Known as "nutria", these invasive South American rodents breed faster than bounty hunters can "control" them. With their orange teeth and voracious appetite they are eating up the coastal wetlands that protects Thomas and his town of Delacroix Island from hurricanes, but the people who have lived here for generations will not give up without a fight.

Cats are cuddly felines and lovely pets, but also highly evolved predators that hunt huge amounts of small mammals, birds and reptiles; perfect killing machines that threaten delicate ecosystems around the world.