Step 1: Pattern Making
After carefully planning out the dimensions on paper, I started by making a quarter of the inside of the noggin covering part of the hat.
After that, I realized that paper doesn't like to be bent into a three dimensional shape. To assist that, I made instead a foam dummy of the shape of the hat as a physical pattern.
Step 2: Construction
The basic point here was to throw fabric on the mold and make it reasonably fit. Cutting and seaming where necessary to make it not be as wrinkled, and integrating curvy bits where needed.
Fabric of choice: White fleece about 1 yard would do. I got two, and have a bunch left over.
Three tips on making your own:
1 If you cut out two curves with the concave sides facing each other, they will make whatever you're sewing bend up. See tail region
2. Sew all the seams on one side, then turn it inside out for nice smooth seams.
3. The chicken is a roundish pudgy creature when sitting. So if he looks lumpy and uneven, that's generally okay under artistic interpretation.
Step 3: Take Out the Foam, and Put in the Personality
Fortunately, due to the properties inherent to foam, all one has to do to extract the form is to cut a head hole and squeeze it out.
This leaves you with an inside out bag of white fleece. Flip the whole thing through the newly created head hole and make sure to poke out the tail so it is nice and apparent.
Step 4: Add Your Noodle
Take the hat and attach it to the inside of the head hole. Sew on a patch to cover the back of the hat, and go have fun with a pseudo fowl on your