Prepare and bake a 1-layer cake mix according to package instructions, except pour batter into a greased and floured 1-1/2-quart glass mixing bowl. Bake for 35 to 40 minutes or until a toothpick inserted near the center comes out clean. Let cake stand at room temperature for 5 minutes.
Remove cake from bowl and cool completely, top side down, on a wire rack.
Cut creme-filled rolled wafer cookies in half at a slight angle. Dip the angled ends of each cookie into some melted semisweet chocolate; place the two dipped ends together on the baking sheet lined with waxed paper to form a leg. Chill until chocolate is set.
Frost rounded surface of cake with chocolate frosting. Add white licorice pastel candies to make a mouth. Place rounded pastel wafer candies on as eyes.
Use frosting to stick candy-coated milk chocolate pieces on as pupils. Cut two corners from red licorice candy; use pointy corners as fangs. Top cake with curly grated milk chocolate. Insert cookie legs into each side of cake.