It's available at some of the usual places, like Missouri Star, or you can go directly to the designer by clicking here.
This is a well-written pattern. The amount of cutting prescribed at the beginning is daunting, to say the least, but once the cutting is done, it is smooth sailing (not the right metaphor, I know) from there.
Actually, I didn't cut everything at the beginning. If I were going to make another chicken quilt, I would cut it all up front. My method got me a tad confused once in a while.