when my sister was in the first grade we dressed her up as a box of cheerios. you can get the appropriate size box at walmart, go in at night when they are stocking on the aisles, they are glad to give them away. we painted it with yellow tempra paint, then cut out the picture of a bowl of cereal from a “real” box of cheerios and carefully lettered the CHEERIOS label.
cut one large hole in the top for her head, an armhole on each side and left the bottom open for her legs. everyone thought it was a hoot but she still holds a grudge against us for that 25 years later! bev