Knead clay into a ball. Place on waxed paper on flat work surface. Roll clay flat to about 1/4" thickness with rolling pin or empty soda bottle. (Keep the shape small and fairly thin or the magnet won't be strong enough to hold it to the refrigerator.)
Ask your child to draw the outline of an animal or any other shape desired with a felt-tipped pen on the clay. Using a craft or kitchen knife, parents should carefully cut out the shape and peel away the excess clay. Gently reshape edges of the shape if they stretch when you peel away the extra. Ask your child to add details such as eyes, a nose, or stripes by rolling small balls of clay or cutting shapes and strips.
If desired, older children may cut whiskers, manes, or tails from picture wire or beading wire with scissors or wire cutter (younger kids can paint them on). Press the wire into the clay at the appropriate place. Using a spatula or your fingers, gently lift the shape and place it on a baking tray. Bake the shape in a preheated oven following the manufacturer's instructions on the package of clay.
Let shape cool. Paint it using poster or acrylic craft paint and artist's brushes. For fine details like eyes and nose, use finer brushes (small children may need help with details). If using poster paint, apply an all-purpose sealer after the paint is dry.
Cut a magnetic strip to fit on the back of the shape. Check to see which side of the tape adheres more strongly to the refrigerator. Then, using glue or a hot glue gun, attach the weaker side of the magnet to the shape. Let it dry.