Heat oven to 325°F. Grease and flour a 9 x 5 -inch loaf pan and two 6-ounce custard cups.
In medium bowl, sift together flour, baking powder, baking soda, and salt. In large bowl, with electric mixer on high, beat together butter and sugar until light and fluffy, about 5 minutes. Add eggs one at a time, beating well after each addition. Reduce mixer speed to low, and add flour mixture in thirds, alternating with milk and sour cream and ending with flour. Beat until smooth. Stir in poppy seeds and lemon peel.
Divide batter among prepared pan and cups. Bake 30 minutes. Remove custard-cup cakes and let cool. Continue baking loaf cake until a toothpick inserted in center comes out clean, about 35 minutes longer. Cool 10 minutes in pan. Invert cakes onto wire rack, and let cool completely.
Trim 1/4 inch off top of round cakes. Frost trimmed tops, and sandwich cakes together. With serrated knife, score diagonal line across each corner of the loaf cake (lines should end about 1-1/2 inches away from corners). Cut wedge-shaped piece from each corner. Trim one wedge into tail. Using toothpicks, secure round cake for head and trimmed wedge for tail. Transfer to serving plate.
Cover entire cake with remaining frosting. Using small spatula or back of a spoon, pull frosting away from cake for a feathered look. Keep face area fairly smooth. Sprinkle cake with yellow sugar. Attach Junior Mints to face for eyes. Add a few chocolate sprinkles for eyelashes. Cut orange slice in half diagonally, and attach as the beak, securing with toothpick. Unwrap Starburst candies, and microwave 5 seconds in batches of four. Knead together each batch; roll out into 3-inch circle. Trim edges of the three circles in wavy design. Bend and attach one circle wavy-side up on top of head for crown. Bend and attach other two as wings. With tube frosting, dot eyes. Tie decorative ribbon and bow around neck, if desired.
Too busy to bake? Substitute a ready-to-serve 16-ounce pound cake loaf and two cupcakes for the cake in this recipe.
In large bowl, with electric mixer on low, beat together powdered sugar, butter, lemon curd, and lemon peel. Increase mixer speed to high, and beat until fluffy, about 3 minutes. Mix in several drops of food coloring until frosting is lemon-yellow. Cover and set aside.