Puffers are smooth skinned while Porcupines have the characteristic spines or quills.
Their teeth are different as well. The Porcupine has fused front teeth while the Puffer has two separate teeth on each jaw. All Porcupine fish love to eat crustaceans, molluscs and any meaty food. Their strong teeth and jaws are designed to crush the shells of crabs and snails, so they are not good tankmates for invertebrates. They will readily accept earth worms, shrimps and crab meat.