The porcupine fish

   This fish is called a porcupine fish because it has sharp spines that look like quills. If an enemy comes near, it puffs itself up into a ball with its spines sticking out in every direction. Very few bigger fish manage to eat it, but sometimes a shark swallows it whole and that's a bad day for the shark. The porcupine fish has knife like teeth, and it can gnaw irs way out of the shark!