You'll need to start this project at least four days before your child's party. For more tips on making papier-mache paste, see How to Make Papier-Mache.
1 large balloon
Masking tape
Flour
Water
Newspapers
Scissors
Aluminum foil
Craft glue
Utility knife
String
Paper clip
Blue tempera paint or spray paint
Black tempera paint
White paint (or white-out)
Small paintbrush
Step 1
Blow up the balloon, but under inflate it slightly. Tie the end in a knot. Stretch masking tape over the balloon to flatten it and make it rounder. Make papier-mache paste by mixing flour and water in a one-to-two ratio. (See How to Make Papier-Mache for helpful tips.) Show your child how to dip 1-inch strips of newspaper into the paste and pull the strips through two fingers to remove the excess. Wrap the paste-covered strips around the balloon, crisscrossing them in all directions. Cover the balloon with just one layer of papier-mache.
Step 2
Make Oswald's legs by scrunching up pieces of aluminum foil into eight tapered tentacles. Turn up the tips of the tentacles' narrow ends and flatten the wide ends. Glue the wide ends to the bottom of the balloon (or use masking tape) and cover them with papier-mache. Allow the balloon to dry overnight. Add a second layer of papier-mache and allow it to dry overnight. No more than two layers of papier-mache is best, because the piñata needs to be thin enough to break when hit with a bat.
Step 3
Pop the balloon with the utility knife and cut a small opening (about 1-inch) in the top of the piñata. (Parents will want to do this part.) Kids can remove the balloon and fill the piñata with candy and small toys or trinkets.
Step 4
Tie a piece of string to a paper clip and tape the paper clip to the top of the piñata just behind the hole. Cover the hole and the paper clip with masking tape. (Use plenty of masking tape to ensure the paper clip stays attached.) Cover the masking tape with papier-mache.
Step 5
Make Oswald's hat from a piece of crumpled aluminum foil and tape it to the top--and to the side--of the piñata. Cover the hat with papier-mache and allow the piñata to dry overnight. Paint the piñata's body blue and paint Oswald's hat black. Allow to dry a couple of hours. Add a white mouth and white circles for Oswald's eyes. After the paint has dried, add Oswald's black pupils.