Nibi is really hard to pixel, I had the most problem with it when I pixeled all 9 Bijuus because in real, it looks flat aswell... as it is most likely a japanese drawing
http://shannaro.files.wordpress.com/2009/09/nibi-no-nekomata.jpg
I like the design and texture, but I can't tell what is what, the depth. It all looks flat to me, like some metal engraving.
Somehow matching your Shukaku quite well, cool :)
this is really cool, i like it