Cut into the Styrofoam head form to alter the eye sockets, mouth and cheekbones as desired. Use sandpaper to smooth out cut sections. Small alterations can be made by firmly pressing the Styrofoam.
Place a roll of toilet paper into a pot of hot water. Squeeze the excess water out. Combine small pieces of the wet paper with school glue. Apply to the face. This process creates a fine papier mache that can be manipulated into a smooth china doll-like finish. Dry completely.
Roll balls of polymer clay into snakes. Vary the length and width of the snakes. Bend into coils or add loops by wrapping around fingers. Lay all the finished snakes on a cookie sheet and bake according to the manufacturer's instructions.
Paint the head and cooled clay snakes with acrylics or spray paint. Include as much or as little detail as desired, for example, the entire Medusa sculpture could be spray painted a solid green, or the face and each individual snake could be carefully painted.
Attach the snakes to the top of the foam head with adhesive such as super glue or tacky glue.
Spray a clear coat of shellac over the entire project. Choose from a glossy, high-shine shellac or a matte finish. Allow to dry completely between coats.
Hammer a long nail into the center of a block of wood. Cover the base of the Medusa head with glue and then press onto the nail to secure the foam head to the base. A solid base will help balance out the design since the clay snakes tend to create a top-heavy piece of art.