I can't believe after the number of years that Everything has been around that SOMEBODY hasn't mentioned Bunnicula.

There were several books, probably most apt for an 8 year old or so, that centered around the lives of a family, their dog, and their pet rabbit. Their pet rabbit was actually a vampire and spent most of his evenings sucking all the color and juice out of the vegetables, leaving behind no trace of his intrusion other than two small holes. He was ... (insert dramatic music here) BUNNICULA!

Anyhow, they were some of my favorite reads when I was a tyke.

A suggestion to prove the existence of Bunnicula. The origin of Cauliflower..! See? Look at the equation below..
Broccoli + Bunnicula = Cauliflower

There you have it.. UNDENIABLE PROOF that vampire rabbits exist!