A 900-pound mountain of muscle, fur, and fury, the grizzly bear can sprint at 35 mph and decapitate a moose with a single swipe. Its claws measure four inches long and its bite can crush a bowling ball. Equally comfortable fishing for salmon or mauling anything foolish enough to wander near its cubs.

A 400-pound wall of pure muscle wrapped in a surprisingly gentle soul—until you threaten its family. The silverback gorilla can bench-press an estimated 1,800 pounds and possesses grip strength capable of crushing a crocodile's skull with its bare hands. Pound for pound one of the strongest animals on Earth, and smart enough to learn sign language while doing it.