I was having to draw some 'How To' instructions for making a CD fish mobile, so I made one to check they worked OK. Sometimes my work is fun!
If you want to make one yourself, there are a number of versions on the internet this is a good one, though the knot in the thread isn't necessary. I just used ordinary sewing thread. Make sure you use really small pleats for the centre fin, or you'll have to redo it - as I did.