Aside from its large size and bright colour, the flamingo's beak is a very distinguishing characteristic. The abrupt bend halfway along the beak allows flamingos to feed comfortably on algae and small invertebrates while standing in shallow water with their head upside down. The key to a great flamingo costume is a convincing beak, appropriately shaped and coloured. Cardboard and papier mache make for a sturdy, lightweight beak.
Cut three pieces from the posterboard in order to create a three dimensional beak: two sides and a bottom. The sides should be shaped like a lopsided boomerang, with one shorter, tapered side and one longer, blunt side. Cut one of the sides, then use it as the template for the other so that they match. The bottom piece should be a long, narrow triangle. Make the bottom a bit longer than the sides so that it can be cut to fit later.
Tape the sides together along the top edge (the obtuse angle of the boomerang). Tape the other edge of each side to one edge of the bottom triangle, resulting in a hollow beak with an open base. Hold the beak over the nose of the half mask, and trim the beak bit by bit until it fits well on the mask. Tape the beak into place on the mask. Trim the bottom edge of the mask, if desired, so that it curves up to meet the corners of the beak.
Mix a papier mache paste of one part flour to two parts water. Rip the newspaper into small pieces, approximately 5 cm (2 inches) square, dip them in the papier mache paste, and use them to cover the joints where the pieces of the beak meet, and where the beak meets the mask. Add papier mache to the sides of the beak as well to make it more rounded. Allow to dry overnight.
Paint the whole mask and beak white to cover the newsprint. Allow to dry, then paint the mask and beak pink. When dry, apply a second coat of pink paint if it seems necessary. Paint the outer half of the beak black. With the black paint or a permanent marker, draw the line between the top and bottom halves of the beak, using a picture of a flamingo as your model.
When the paint is dry, add pink feathers to the temples of the mask. Use larger feathers at the outer edges, then smaller feathers as you get closer to the eyes. Overlap smaller feathers on top of larger feathers.