This is a project I did as a child -- it's from my old copy of Making Things by Ann Wiseman. I don't have much from my childhood, so it's especially neat having this book. I doubled up some large paper from the easel and cut out two large fish for Maia to paint. If I had had a large roll of butcher paper, I'd probably use that, but the easel paper worked fine.
Maia painted each fish very differently, starting with a black marker drawing on one. We hung them up to dry, then glued them back to back with a thin line of glue all around the edges, leaving about six inches open at the bottom.
After letting the glue dry overnight, Maia and I stuffed the fish from the hole on the bottom.
We started out using scrunched up paper towels, but it was taking more than I expected and felt a bit wasteful, so then we scrounged in the paper recycling and used scrunched up pieces of paper instead. We glued it shut, then held it closed with clothespins while it dried.
I punched a hole in the top, and hung the fish sculpture in the dining room. I think we need a couple more of these for a nice big fish mobile!