Place cookies on cooling grid positioned over cookie sheet. Thin green and white royal icing to pouring consistency. Cover candy corn with white icing and Frankenstein with green icing; let dry. Use tip 3 and royal icing to pipe whites of eyes, green eyelids and nose. Use tip 2 and black icing to pipe eyebrows and earrings. Use tip 3 and red royal icing to pipe mouth; add tip 5 green royal icing cheeks (smooth with finger dipped in cornstarch). Use tip 4 to pipe hair in gray (use a small amount of black) and white royal icing. Let dry.
Attach head and body cookies with white royal icing and position on waxed paper-covered surface to dry. Use tip 4 and white royal icing to pipe arms (smooth with finger dipped in cornstarch). Pipe tip 3 hands with green royal icing. Pipe tip 4 feet with black royal icing.
Combine Leaf Green and Lemon Yellow icing colors for green shown. Combine Red-Red and Christmas Red icing colors for red shown. Roll out cookie dough and use candy corn and Frankenstein cutters to cut cookies. Bake and cool.