Nifflers are black, furry things with long snouts and shovel-like paws. They are living treasure detectors, and basically spend all their time diving into the soil, looking for gold. ron wants one as a pet, but as Hagrid says, they wreck houses. Still, they're cute, aren't they? And, though they only appear in one chapter, they're a lot more fun than, say, ron himself, or the centaurs. *Sigh* I wish I had one...