Cut 1 cake in half. Arrange whole cake and cake pieces on large tray or foil-covered board to resemble dog's head and ears as shown in photo.
Frost round cake with COOL WHIP, then frost ears with chocolate frosting.
Spoon melted chocolate into small resealable plastic bag. Cut small piece off one bottom corner of bag; use to pipe chocolate onto round cake for dog's eyes, nose and mouth as shown in photo. Add gummy candy for the tongue.