5. Grey Wolf
Wolves are endurance athletes, capable of covering dozens of miles in a day, with extreme cold tolerance (they can comfortably sleep, exposed, in temperatures as low as -40). While they prefer to hunt smaller, weaker prey, wolves can and often do take on elk, moose, and even bison. A grey wolf’s bite strength is 1,500 pounds-per-square-inch—about twice the force of a German shepherd’s jaws.