This tutorial will show you how to make a hollow shape by forming clay around a balloon. This time will make the hollow sphere into a piggy bank.
Any brand of air-dry clay that you can roll into a flat sheet is suitable for this project. Some of the very soft marshmallow-like clays would not be a good choice because they're too sticky to roll into a sheet or to coil.
This demo shows a terra cotta colored pig, but, of course, you can use any color clay you wish. Use acrylic paints or other medium to tint your raw clay before shaping or paint the pig when cured.
If you have trouble with the tail or ears staying on, just adhere with white glue!