porcupine

Porcupines are large herbivorous rodents with a coat of sharp spines, also known as quills. These quills are actually strands of hair coated with layers of keratin, a form of protein found in skin. The quills function both as camouflage but also as protection, as the hard sheath of keratin tapers into barbed points, making the porcupine appear sort of like an elongated pincushion.