I've got a theory, it could be bunnies...

I've got a theor-

Bunnies aren't just cute like everybody supposes
They've got them hoppy legs and twitchy little noses.
And what's with all the carrots-?
What do they need such good eyesight for anyway?
Bunnies, bunnies it must be bunnies!

...or maybe midgets...

Auteur: Joss Whedon