1.Grease 26cm x 36cm baking dish (base measurements), line base with baking paper. Using three packets, prepare cake mix according to directions; pour into prepared dish. Bake in moderate oven about 1 hour. Stand cake in dish 5 minutes; turn onto wire rack to cool.
2.Use paper pattern, cut out whale; reserve leftover cake. Using a toothpick or skewer, mark out belly on cake. Place cake on board.
3.Tint half the butter cream with royal blue colouring.
4.Following pattern, spread belly with 2 tablespoons white butter cream.
5.Swirl blue butter cream into remaining white butter cream gently to create a marbled effect. Carefully spread marbled butter cream over cake.
6.Cut spout and flipper from reserved leftover cake and position on cake; spread with more butter cream.
7.Sprinkle blue sugar crystals on and around the flipper, tail and belly. Sprinkle white sugar crystals on spout. Cut a thin strip of licorice for mouth and place in position. Cut eye from remaining licorice; position on cake. Secure blue M&M on licorice with butter cream.