5. Gorilla (1,300 psi)
Gorillas are the largest of all our primate cousins. With huge, muscular, tree-trunk-like arms and enormous canine teeth biting down at a strength of 1,300 pounds per square inch, a 400-pound silverback (adult male gorilla) certainly cuts an imposing figure. That said, these gentle giants are little threat to people. They are herbivorous, peaceful and generally shy in the presence of humans. But silverback troop leaders will engage in combat should they meet and come into conflict in the wild, and these fights are often to the death. It’s in these situations that the ferocious teeth and formidable bite of the gorilla come into play. Gorilla-on-human attacks are not entirely unheard of, either, although these usually take the form of self-defense or, in the case of a zookeeper in Buffalo, N.Y., who was bitten by a gorilla last spring, “love bites.” Even though reports indicated the bites in this instance were intended to be playful, they sent the keeper to the hospital, and a SWAT team had to be called in to tranquilize the gorilla. Chomp!