Yara was a great warrior who belonged to an indigenous tribe, located in the north of Brazil. She was the only daughter between three brothers and her strength and bravery make them jealous, since their father only praised Yara. One day, the three brothers decided to kill her. Luckily, Yara heard their plan, unable to believe that her beloved brothers hated her so much. When they attacked, she killed them instead. Afraid, she run away to the woods, but soon the bodies of the three brothers were found. The tribe searched for Yara, tirelessly, but her father was the one who found and captured her. As a punishment for the murders, he threw her in the Solimões river and told everyone she was also dead.

The legend tells that something magical occured in that river. It was a full moon night and the fishes around Yara's body turned her into a beautiful mermaid. When a man passes near the river, she starts to sing and then he fall in love immediately. But, when he come close, she drowns him, taking his body to the bottom of the river. Yara was cursed to never believe in any other men who says to love her.

Years passed and still this legend is famous around the country. Some local women claimed they have seen a mermaid near the surface and in full moon nights they can hear a song coming from that river.