Beat the egg whites with an electric mixer until soft peaks form. Gradually add sugar a little at a time while mixing on a high speed, or until firm peaks form.
Divide mixture into two portions, stir in a few drops of red food colouring to one portion, and a few drops of green food colouring to the remaining portion.
Pipe into chosen critters, bake in an oven at 120c for 45 minutes or until critters are dry to touch. When the critters are cooled down you can now decorate them with icing sugar and chosen sweeties.