[@BlackPanther]
(I really liked your character btw) I came across a tail like the one you described (it was actually the one i was going to use for my mermaid but then i found the other one!) anyway: [url=http://img03.deviantart.net/c53b/i/2012/212/c/3/mermaid_tail_07__black_koi__by_deviantroze-d59cxke.png]A fin like this perhaps[/url]
(the artist even used a koi as the model for the tail! :D )