Slug Evolution.

Here's the original drawing I made for a spread in my (wanna be picture) book.  

At full size, it looks flat.

  I scrapped the lines and added some stylized shading and texture:

 Then I added slime:

The image  was one  I showed in my portfolio review.* The person doing the critique noticed  that the yellow slug had a  similar color value as the background grass.

Desaturate the image, and he's stealth slug!

 I played with the values, double checking the corrections in black and white:

 Here's how it looks now.  More changes to come, I'm sure.

*At the SCBWI 2013 Summer Conference.