I used cardboard for the entire costume. Took a piece of string to get a proper sized circle, then cut out the pie. Then I used a roller to form a long strip which I adhered to the discs with tape. I had a cardboard roll from something which worked well. Large piece of PVC or something would also work.
I used duct tape to seal it all together inside and out. Painted the outside yellow and got a couple yellow long sleeve T-shirts. Used measurements off my wife and I for height and width. Pretty easy just a little time, about 3-4 hours including paint drying. The bottom has an entrance and top has enough room to stick your head thru with your arms sticking out.
The costumes were a hit and we wore them for quite a long time at the party, enough to dance and enough arm movement to drink. They have to be taken off to use the restroom, but on and off is quite easy.