Can we have some evidence to support these claims of people who have accomplished such magic. If there are people out there that can transform them self into a mermaid were are the pictures?
Spells to turn yourself or someone else into a different creature are not realistic. This is called role play and should not be confused with actual magical workings. I suggest doing some research about magic and the things that can be accomplished with it. If you actually take the time to do this you will come to understand how magic effects someone's life and what realistic expectations you can have when practicing magical workings.
By the way congrats Stoni on being the latest mermaid specialist.