Book excerpt: Imagine a creature that would gnaw on the tail of a crocodile or crush a seal's skull with its razor-sharp teeth. Are you picturing a grizzly or other tough-looking critter? If so, you're wrong! The animals that do these things are none other than adorable otters and fluffy polar bears! Many adorable animals can actually be pretty vicious. Find out which cuties are killers and see how they take down their prey.