Draw a hole big enough for your lil one's head on one end, leaving a little space for his shoulders to be able to "carry" the costume, and another hole on the other end that is big enough for his whole body to go in. So sort of top end and bottom end.
Draw two same size holes on both sides of the cardboard for the hands.
Cut these holes with either knife, craft cutter/knife or scissor.
Cover the whole cardboard with white craft paper, secured with either sticky tape or stapler, not forgetting to also cut holes for hands on the sides.
Then with red gorilla tape, make stripes as shown on picture, just like a popcorn box/bucket motif.
On the shoulder area and also on red head, place double side sticky tapes every where, generously
Crumple tissue papers and stick them to the shoulder's are and also on the hat - and these are your popcorn to be