Place the 9-inch cake in the middle of a 15x13-inch covered board to assemble. As eyes, place two cupcakes atop the cake. Make legs out of sponge cakes and place them underneath the cake. To make the feet, cut one cupcake in half using a zigzag cut. Place each piece on top of a sponge cake, with the rounded edge touching. (Reserve any leftover cupcakes for another purpose.) In a small saucepan, mix together the flour and milk until smooth. Bring to a boil and simmer, stirring constantly, for 2 minutes, or until thickened. Cool. In a small mixing bowl, combine the butter, shortening, sugar, and vanilla extract. 4 minutes later, add the milk mixture and beat until smooth.
