The arrival of the Siren
Born of spite and spurn the siren were once members of the other merfolk ethnicities. When their chosen lovers chose another they felt spurned and turned spiteful. This caused their physical appearance to take on a hideous aspect. They have chosen to destroy all men they can. They use their voices to lure men, particularly sailors, to their deaths in the briny depths.
Long time ago, before we had written history, there was a young mermaid. She was considered to be the most beautiful of all the merfolk. It seemed that if she wanted a young man she would have him. That is until one day there came a man who refused her attention. She tried everything in her power to draw his gaze to her but his heart was already given to another. When she learned of this, she swore she would have him for her own no matter the cost. Her fellow merfolk tried to disuade her of these actions only to be rebuffed. She spent many months trying her wiles to get the man and failing each time. With each attempt she became more brazen, and angry. One day the lady to whom the man's heart was given came down to the shore. She rivaled the beauty of the sea. This made the young mermaid angry and in her anger she turned her wiles to the lady. Though the lady did not succumb, she did approach to speak with the mermaid. When she was close enough the mermaid struck out at her with her teeth and hands. With this action she was forever changed; her teeth became like daggers, her nails like claws, and her countenance became dark with her eyes sucken. She bit into the lady's neck and drained her of all blood. Taking the body to the depths she hid it in a cave never to see the light of day again. When her people learned of her actions she was driven from their community to roam the seas alone. She did return to the cove where she had first seen the man. He was searching the beach for his love. Because of her devouring of the soul of his love she was able to take on her appearance and voice, she called to him. Hearing the voice of his beloved he approached. This newly formed siren mated with him before she drowned him in the briny depths.
This is a tale of how the first Siren became. It is used as a teaching method for young merfolk to beware the dangers of pride and greed.
This is deeply rooted in actual history with the first siren being forced out of her community to face the world alone in exile for her crimes.
Variations & Mutation
There are remarkedly very few variations of this myth. The one that is the most common is that the siren did not kill the lady but convinced her that her man didn't truly love her. Upon hearing this the lady ran away and committed suicide in the forest.