The double portion of luck with twins
Take a white carton and cut a square out of it, approximately 20 x 20 cm. Draw a bathing tube in the middle which you give little cuts on the sides so that you are able to fix a folded bill there. Then you draw or glue the two funny guys on the carton and give them an identical look and a rubber duck in the middle. You can write a good wish on the bottom.
Of course you could fill the bathing tub with three kids or just with one.