This is a crazy popular costume that I created a few years ago.It is the most popular image on google images. I have dozens of people contact me to ask for a pattern or a finished costume. I decided to write an instructable so I can direct people here.

Supplies

See step 1

Step 1: Supplies

sewing machine
Needles for machine
Thread to match fabric
Teal flannel for the body -1 yard for a toddler, about 2 for a 5-10 year old, 3 for a large child or adult
Teal fabric for the tail- 1/2 yard for a child: 1 yard for an adult
Red flannel for headpiece 1/2 yard for all sizes
Yellow polar fleece for headpiece and cowl- 1/2 yard all sizes
1/2 elastic- 2 feet- 3 feet
Measuring tape
A plastic ornament ball
White spray paint
Green, yellow,white and black craft paint for eyes
Polyurethane spray for eyes
Half inch flexible plastic tube-2feet
Tape
Beacon Fabric glue
Velcro- 1 foot sew on Velcro
Yellow tights
White canvas shoes
Scissors
Ruler
Large paper-Butcher paper, wrapping paper,
Pencil
Sharpies: red, blue

Small and medium boxes
Box cutter
Chicken wire
Wire cutter
Red , black and white paint
Brushes
Faux flowers

Step 2: Make a Pattern and Sew Body

To make a pattern you will first need to take measurements of the wearer.
Measure from shoulder to crotch . Add a couple of inches to that number.
Measure around the waist , chest and hip. Go by the largest measurement and add a couple of inches.

Lay out your paper and make a grid of one inch squares. You need as many squares as you measured in inches.
Going by the image above cut out 2 each of the 3 larger pieces and 4 each of the rectangles.

Draw the pieces on the paper keeping the pieces in perspective.

Cut out the paper patterns you have created. There are 5 different pieces . Now is the time to draw on feathers with the blue sharpie.

For the chest and shoulder straps:
In the second photo you will see how the pieces go together . There will be 2 sets. Sew the sets together right sides together: sew all the way around except the bottom edge. Be sure when you sew the 2 sets together that you fold the long triangles down first. Clip curved edges.

Turn the top right side out.
Press.

For the bottom pants of the costume sew the front 2 pieces together at the curved edge . Sew the back 2 pieces together at the curved edge, but leave the top open . Stop at the dot.

Open both sets and put right sides together. Sew the crotch and side seams.

Fold over the bottom edge and sew a 3/4 space for the elastic.Leave a one inch opening to insert elastic. When cutting the elastic make sure it is going to be loose on the wearer.

Feed the elastic through the tunnel . Sew ends together and sew opening shut.

Gather the fabric on the top of the pants from back opening to back opening. Place the pants over the top matching side seams and center front on top to center seam on pants. Adjust gathers and with right sides together sew top to bottom. Turn right side out.

Sew Velcro to the back waist and the tips of the shoulder straps.

Step 3: Eyes

The eyes are made from plastic ornament balls cut in half.
I used a miter saw to cut mine.

Cut a piece of tubing that is just shy of the cut area of the ornament.

Spray the cut ornaments with white spray paint. Set aside to dry.
Tape the tubing into a circle.

Cut a circle of red fabric that is 2 inches larger than the tube ring. Place the ring on the fabric. Glue the fabric to the ring. Allow 5 minutes to dry. Cut the fabric in the inside of the ring like an asterisk. Apply glue to ring and fold the triangles of fabric over the glue. You may have to cut off the tips of the triangles.

Once the spray paint dries paint the pupils and irises onto the eyeball. Make sure they don’t match up. He is supposed to have wacky eyes.

Allow eyes to dry . Spray with polyethylene.Allow to dry.

Slip ring over eye and glue in place.

Step 4: Headpiece

Cut out 2 red fabric for the top of the headpiece and 1 yellow for the bottom.

Use a red sharpie to draw on feathers.

Sew the top 2 pieces together leaving the curved facial area open . Right sides together sew the yellow to the red . Stuff the top of the red crown . Glue a piece of scrap fabric on the inside to keep the stuffing in place.

Glue the eyes onto the sides of the head.
Make a beak out of 3 triangles of yellow fabric.
Sew on Velcro at the yellow neck area.
Using a scrap of red fabric, cut a 2 inch by 8 inch rectangle.Fold in half. Sew all but one inch all the way around. Turn fight side out and glue onto the beak.

Step 5: The Box

Using one small box and one medium box , cut out the openings as shown in the photos.
The larger box has an angled roof with a large semicircle removed for the rooster to stand.
Paint the boxes your desired colors. Paint on details.
Glue on flowers.
Glue chicken wire to small coop.
Print out scared chicken images and glue to chicken wire.