The hippo in a coat on the cover looks interesting enough for me to get the book. I've no idea what Elephantmen is. Well, according to wikipedia, The Elephantmen series is a spin-off from the series Hip Flask, set in the same universe and expanding on details of various minor characters from that series.
This book is the concept art book for the comic series drawn by José Ladrönn. Since the story is character based, there are tons of character designs for the unhumans as well as the humans. These are sketches, lineart, paintings and character profiles. There are lots of iterations included and you can see what works and not, and they are all explained.
Particularly impressive are the ridiculously detailed paintings which took months to draw. There are several pieces and each are shown with the work-in-progress shots from sketch to the colouring stage.
In some of the drawings, 3D models were created to help in painting the environments and vehicles. These 3D screenshots, with wireframes, are also included. The amount of effort and work is just staggering. Many of these are just going to appear small in the final art anyway but still...
Dedication screams out in this book. This Ladronn guy really works hard for his money.
There are more pictures of the book on my blog. Just visit my Amazon profile for the link.