The Black Caiman
Though it may look similar to the American alligator, this beast - the largest predator in the Amazon - stands on its own in terms of fearsome features. Lurking in the rivers, lakes, and other freshwater habitats of South America, the black caiman has been officially measured at a length of 16 feet and weight of 880 pounds, but locals swear it can reach up to 20 feet and an astounding 2,400 pounds. With no natural predators, it plays an essential role in regulating the Amazon's ecosystem, leading many to consider it a keystone species for foodchain management. Gobbling up anything from snails to the largest terrestial mammals, this is one animal we're keeping our distance from.
What if they lost interest in monkeys and anacondas, and instead took an interest in humans? Take the wild ride with Zoo and see what can happen when animals organize and revolt.
(Corbis/ Frans Lanting)