Using the Leg Single Crochet. (Rosss’s stitch :)).
The pattern has an excellent photo tutorial on how to do the stitch including increase, decrease and color changes.

Biggest note: Crochet loosely !

The leg single crochet makes a really tight woven fabric when you’re done .. so you don’t have to work as tight as you would have with normal single crochet (so going down a hook size for this snake is not recommended)

My kid loves the diamondback snake and couldn’t wait for it to be finished

Notes on my diamondback Rattlesnake:

• Made the snake longer by adding 33 rows
• I used the bigger diamond design provided in the pattern
• Colors were chosen based on the Easter Diamondback rattlesnake (as pictured by the Safari ltd toy :)
• Rattle made with 4mm hook (as per the pattern)