Heat oven to 350F. Grease and flour 1 layer pan 8 x 1 1/2", and 1 baking pan, 9x9x2". Prepare any flavor layer cake mix as directed on package, except - divide batter evenly between pans. Bake 8" round 30 to 35 minutes, 9" square 20 to 25 minutes.
Cut a circle about 8" in diameter from square cake; cut 4 small half-circles for ears and paws from corners of square cake. On large tray, arrange round layer for body and cut the pieces for head, ears and back paws. Place 2 large marshmallows on body for front paws.
Reserve 1/2 cup frosting from 1 can vanilla ready-to-spread frosting. Frost head and body of bear with remaining frosting, joining pieces together.
Blend 1 oz. melted unsweetened chocolate (cool) into the reserved frosting. If frosting is too stiff, blend in few drops water.
Frost ears and paws; make circles for background of eyes with chocolate frosting. Cut large marshmallow horizontally in half for eyes; place half on each chocolate circle. Use chocolate pieces for pupils of eyes and for buttons.
Cut black shoestring licorice for claws, use black gumdrop for nose, red shoestring licorice for mouth and red gumdrop slice for tongue.