The mermaid is a staple in many folk tales. It's the story of a half-fish-half-woman who sometimes brings luck and sometimes misfortune.
She might fall in love with a human and, from time to time, she hangs out with mermen. It turns out she has quite a fan club.
Last month, hundreds of people got together in South Carolina and togged up in custom-made fishtails to swim and perform underwater.