Porcupines are very cool animals! They have very spiky backs, similar to that of a hedgehog. Porcupines (along with capybaras) are the largest members of the rodent family, and tend to have buck teeth.
Porcupines, if threatened, can get their quills lodged in the predator. And, if that isn't enough, the porcupine also secretes a foul liquid that stinks of burning tyres.