Dont feel restricted coz you dont have the cake tins....besides costing a fortune, you can easily cut the shape out of the cake itself - easy peasy.

I did a #1 for my DD#3 covered in smarties.....just baked 2 bar cakes (like loaf tins), froze them, then will semi thawed...cut them into shape.....very easy.

YOu could always search for cupcake toppers that resemble ducks...etc....cook up a batch of cupcakes, buy yourself a cupcake stand, and believe me, it will look fantastic.

GL !!!