I've been drawing some fish on muslin, stacking some batting inbetween the front and back and machine stitching around the edges. The plan is to place a washer inside the fish and then have a magnet lure to catch the fish with. So far...I think it will work. I'm keeping the batting pretty thin and the fish pretty light weight so they should be "catchable."
And I'm pretty sure the girls are guaranteed to like them. They've already run off with the clownfish prototypes and are requesting more. Phew!