This instructable will mainly describe how to make the rooster hat. The Robot Chicken hat is made exactly the same way just with a different beak and with some tin-foil adornment. I will also show a couple of the other very simple extra pieces I made. The Robot Chicken costume in its entirety took about 5 or 6 hours to make (exclusive of purchasing the materials).
Step 1: Gather your ingredients
Felt - yellow, white, red, black. I used mainly stiff felt produced by Eco-Felt. I think you could use soft felt for the hat, but the beak and the comb need to be stiff. The felt comes in roughly 8.5 x 11 sheets of which you will need 2 sheets to make the hat, 1 for the comb, and one for the beak. Each sheet of stiff felt should be somewhere around 75 cents. Soft felt will be cheaper.
Needle and Thread - regular and/or embroidery thread in a variety of colors that match the felt.
Scissors, glue gun, scrap paper, something red and possibly sparkly