very simpatic. bravo

Post working source links.

Author, you need to post a link to each source you use to show they are public domain or creative commons images, and not copyrighted. Please read http://www.pxleyes.com/blog/2009/06/how-and-where-to-find-legal-source-images/
The link you posted doesn't lead to an image.

Nice -- maybe some softening of the edges of the cow , head dress and neck piece

Congrats!!

You spend just enough time to come up with a rough sketch, but lack finishing it. This could turn out interesting, but right now, there are too many rough parts for me to judge it well. Take your time, work out the details, and finish it...you will be much more happy with the results.

I like it but feel as if the shadows should've been worked on a bit to match the rest of the image. The DOF here is a little sketchy as well... Otherwise clever!

Why blur the background when it's not blurred in the source image?

Illustrations not created by yourself can't be used. See http://www.pxleyes.com/guidelines/photoshop/
5.7. 3D Renders or Illustrations as Source: Using other people's 3D renders or illustrations (even with permission and no matter in which form they are offered) creates a false impression of your artwork. So 3D renders or illustrations (this includes brushes, tubes, clipart, pdf files) can not be used as sources, unless they are entirely created by yourself.