Step 2: Make the Body
Next the end cap was added. This too had flanges that were used for gluing to the body section. A square shaped hole was later cut into this end cap to allow my son's head to fit through.
Arm holes then need to be added on the side surfaces. Make these oversized to facilitate the process of putting the costume on and taking it off.
Tip: score the cardboard before bending to allow for much cleaner folds.