Make cupcakes. Prepare batter following recipe directions. Bake and cool cupcakes.
Ice cupcakes. Prepare buttercream icing following recipe directions. Tint a small portion of icing black; tint remainder green. Use spatula and green icing to ice top of cupcakes smooth.
Decorate cupcakes. For each cupcake, cut 18 pieces of shoestring licorice, each 2 in. long. Insert pieces into top of cupcakes. Use tip 3, cut disposable decorating bag and black icing to pipe eye line and to outline and fill in mouth. Pat mouth smooth with finger dipped in cornstarch. Use black icing to attach candy eyeballs onto cupcakes. Insert knife icing decorations in cupcakes.