Heat oven to 350°F. In medium bowl, knead cookie dough and flour with hands until well mixed. On floured surface, roll dough to 1/4-inch thickness. Cut with 3 1/4-inch egg-shaped cookie cutter. On ungreased cookie sheet, place cutouts 2 inches apart. Reroll dough and cut additional cookies.
Bake 9 to 11 minutes or until edges are lightly browned. Cool 2 minutes; remove from cookie sheet to cooling rack. Cool completely, about 15 minutes.
Spread yellow icing over each cookie to cover. Near top third of cookie, attach candy corn tip for beak; let stand until set. Pipe white icing on bottom half for broken eggshell. Let stand until set. With black icing, pipe eyes. With yellow icing, pipe tuft of hair at top. Decorate shells as desired with blue icing. Let stand until set.