Bake cookies one day ahead, using star cutter. Cool.
Thin a portion of white royal icing to pouring consistency using water, a teaspoon at a time. Place cookies on grid over tray and cover with icing; move cookies to wax paper covered board to dry overnight. Save leftover thinned icing.
When cookies are dry, brush edges with thinned icing and dip cookie in yellow sugar. Set aside to dry. Pipe tip 12 head. Using tip 1, add string mouth and eyes, dot nose and cheeks. Pipe in tip 2 hair and halo. When dry, attach cookie stick to back of cookie with icing. Let dry.