'Arthur Spiderwick's Field Guide to the Fantastical World Around You'. BRILLIANT.
'Spiderwick Chronicles' by Tony DiTerlizzi and Holly Black??? Well, when I was looking up the links to those books, I also found that this lovely book exists. And when my kid sees it, she is going to LOSE HER MIND. She loves this kind of thing.
A year ago, 'A Dignity of Dragons' was Julia's very favorite book; she spent days and days and days poring over the different kinds of mythological creatures.
The 'Spiderwick's Field Guide' book helpfully outlines pertinent information regarding a variety of magical and mythological creatures, such as kelpies, the common house brownie, and the black phooka. WHAT IS A BLACK PHOOKA????
Basically, an incredible field journal of imaginary beasts. (who says they're imaginary???) I'm stunned by the coolness. (oh the cool book i mentioned in this post? that book is not this book. that book i'll show you asap.)