Procedural Content: SnakeSkins

I was looking through a book of snake illustrations, and it occurred to me that snake skin textures are a great candidate for procedural generation. I've hit upon an approach that seems to hold some promise and started coding it up with Python (no pun intended- just like the language) and the PIL (Python Imaging Library).
All of the images below are purely procedurally generated.

Below are some examples from the first pass, just black-on-green.

After that, I started playing around with colors, with lots of fun results. Still needs some work, but looking promising so far.