I started writing this book about an old Brazilian myth called Encantado.
The myth talks about Encantado who would lure humans to their deaths (Similar to sirens and mermaid myths). It was how many people would explain disappearances in the Amazon. The myth is dark and gruesome. Some myths state that Encantado can be spirit forms, some say snakes, but commonly it is freshwater Dolphins.
One of the things I love about this myth is their abilities. The ability to be a superior musician (because who doesn't love that?), the ability to seduce unsuspecting humans (because there is no good myth without an unsuspecting human), the ability to turn humans into Encantado (because everyone needs a nice healthy fear, right?), and lastly the ability to inflict insanity and even death.
I may have taken some creative liberties with the story but it is such an amazing story that people should hear about.
Just to add to my point here's an awesome picture of a freshwater Dolphin :-)