Need:

Plastic hoisery eggs
Poster paint
Liquid soap
Clay or playdough
Accessories-felt, glitter, rick-rack, etc.
Craft sealer (optional)

Mix a little liquid soap to poster paint to help it adhere to the plastic, then have child paint both halves of the egg to look like Santa, an elf or whatever he wishes. (The eggs will be easier to paint when separated in half.) When the paint dries, put a ball of clay in the bottom half of each egg and glue the parts together. Have child add finishing touches to the roly-polies with paint, felt, glitter, etc., then coat with craft sealer.