Encyclopedia Entry:
A type of Harpy with a beautiful singing voice that absolutely loves singing. Her songs are infused with a lot of magical energy, and men who hear them become entranced by it and end up moving in the direction that they hear the song coming from. Most sirens live near the ocean, and due to this many ships have disappeared mid-voyage, never-to-return, after the men aboard were lured by their songs. Thus sailors are very fearful of them.
They choose their prey from among the men who were drawn to them by their songs, but in this case, they aren’t the only threats. Most of the time, all kinds of monsters who are after the men are lurking nearby. Once the songs have ended, the men who were entranced by the songs will be attacked all at once, and will probably end up being taken away.