Weighing in at a staggering 14,000 pounds, the African elephant is the largest land animal on Earth and a living battering ram wrapped in two-inch-thick hide. Capable of flipping cars and toppling trees on a whim, its intelligence rivals that of primates—complete with mourning rituals and long-term memory. Cross one and it will remember your face forever.

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.