Grease 2 baking sheets. Copy the owl picture opposite to make a simple template about 5 cm (2 inches) high.
Roll out the cookie dough on a lightly floured surface. Lay the template over the dough and, using a small, sharp knife or scalpel, cut around it. Reroll the trimmings to make 18 in all. Place on the baking sheets, spacing them slightly apart.
Beat together the egg white, cocoa powder and measurement water to make a smooth, thin paste. Using a fine paintbrush, paint the wing, head and beak areas on the owls. Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 15 minutes, or until pale golden. Transfer to a wire rack to cool.
Beat the royal icing sugar with enough water to give a consistency that holds its shape. Put the royal icing in a piping bag fitted with a fine plain nozzle. Use the white ready-to-use icing to shape eyes, then secure them with a little royal icing from the bag. Use the blue icing to shape centres for the eyes, then secure with royal icing. Cut out feet in yellow icing and secure. Use the icing left in the bag to paint the wing and breast feathers. Leave in a cool place to set for about 1 hour.