Porcupine

mammals · rodents · prickly

Quills are special hair. A porcupine's sharp spines, called quills, are actually modified hairs made of keratin, the same stuff in your fingernails.

Built-in armor. Those rigid quills protect porcupines from predators, making them tricky and painful to attack.

Two separate families. There are Old World porcupines and New World porcupines, and even though they look alike, they aren't closely related to each other.

A big rodent. The largest porcupine is the third-biggest rodent on Earth, after only the capybara and the beaver.