This costume took a little longer than expected because of cutting all the small shapes out. I spent about $6 on fabric and $4 on foam. I also used hot glue, cardboard and paper mache. I made this a lot like I did the Minion costume. You can find this costume and all my others on www.JJsHalloweenOutlet.com
I used an exercise ball to use for the form of the head. I covered half of it with about 4-5 layers and let it dry overnight. You could also use a large punch balloon. The size I made will fit an adult up to about 200 pounds. So if you're making it for a child I would use the balloon instead. I covered about half of it in paper mache. Alternating colors to make sure I have compete layers on it.