To cover the potentially sharp top edge of the soup can neatly, cut the rectangle of felt 1/2 inch taller than needed to cover can. Glue the felt to the can matching the bottom edge of the felt to the bottom of the can. Cut the felt to the top edge at 1/2-inch intervals. Carefully spread glue inside the top edge of the can and press down each tab of felt overlapping as needed.
Some octopuses turn white when they are scared and red when they are mad.