House rabbits are 100% VEGAN + GREEN companions.
House rabbits eat 90% hay,
green veggies + a little bit of rabbit pellets 2 x per day.

They're litterbox trained (if spayed/neutered) 
and quiet.

They have no animal odor, they're 99% non-allergic, have no dander
and clean themselves scrupulously.

They poop and pee on hay that makes great organic garden fertilizer.

plus you get binkies and nosebonks.   
http://rabbitmatch.posterous.com/the-real-energizer-bunny

RabbitMatch is a 501c3 project of SaveOurPlanet.org.  We're an all-volunteer nonprofit that rehomes house rabbits.