The scales texture in the sssnake! project was created with the aid of a splendid new tool from Astute Graphics. Collider Scribe is a £10 add-on for Adobe Illustrator designed to help lining up and arranging objects in your illustrator projects. It make short work of arranging these various sized circles so that their edges are accurately touching. Here's how. 

Create a long thin shape for the snakes body. Draw out some circles of decreasing size. These will be used as a the scales. I used the same fill colour as the body and a lighter colour set at 2pt for the stroke.

<Shift> drag a row of the larger circles up the centre of the body. This is where the Collider Scribe tool comes in. As I shift drag a shape it snaps into position onto any shapes it comes near, This makes it really easy to position shapes so that they are just touching.

Use the Collider Scribe tool to fill in the remaining shapes positioning larger circles in the centre and smaller shapes towards the edges. Let Collider Scribe snap them into position for you! 

Once the body is full of circles it is time to change their hues. I used this free script to change the colours randomly. Download it and save it to your computer. Select all the circles, but not the background then select File -> Scripts -> Other Scripts and select the Vary Hues script from your computer.

This is the result after running the script with and input value of 25.

Complete the snake skin by adding a clipping mask to trim off any excess circles.