WOW! Where was this when I needed it last Halloween? My daughter not only demanded a mermaid tail for Halloween, she also wanted it to be "store bought" (I usually make her costumes). So I gave in and paid $30 for a mermaid costume similar to this one that fell apart the minute she put it on. There were sequins all over the house and needless to say, months later we are still finding them.
Sew Homegrown: Simple Wrap-Around Mermaid Tail