It makes sense that a filmmaker with the conceptual ability of Guillermo del Toro (now working on a dark version of Pinocchio, director of Pan’s Labyrinth) would also have an exquisite eye. Here are a couple of del Toro’s wondrous sketchbooks.
See a good profile of del Toro and the film, here.

Wow..fabulous… good find! Do you ever wonder what H.R. Geiger’s sketchbooks look like?
Love your blog….
Comments like yours are the reason I love blogging. No, I had never wondered, but when you mentioned it, went looking and found this! Fabulous.
http://www.littlegiger.com/limited/items/book_ske.html
Thanks, never would have found it otherwise.
Yikes, that is a beautiful/scary rabbit hole…!
The yam-thing reminds me of the mandrake in harry potter.
Nice catch. Sure does look like the mandrake. Thanks for taking the time to point that out!