Grizzly bears are massive; some weigh as much as 1,700 pounds (771 kg) and stand 10 feet (3 m) tall. They eat pretty much anything, from berries and nuts to fish, and even the occasional moose. A grizzly will take on a human if he or she gets in the way of offspring or sources of food, but grizzly attacks are rare. And that's a good thing -- the force of a grizzly bear's bite has been estimated at between 975 and 1,160 pounds per square inch, enough to do considerable damage to a bowling ball.
Their jaw strength falls somewhere between that of a lion and a tiger. There are more powerful animal bites, though. Gorillas (1,300 psi), jaguars (1,350 psi) and hippopotamuses (1,825 psi) all have stronger jaws. The baddest biters, however, make their homes in or near water -- the alligator can attack with a 2,125 psi bite, the saltwater crocodile's crunch is 3,700 psi and it's been estimated that a great white shark's chomp could be as high as 4,000 psi.
More about grizzly bears: