Tonra was a purple tailed merman. He was the only merman Jack Sparrow had ever seen. Tonra led young Jack to a room that had crystals surrounding the whole room. They were crystals that controlled the merfolks' freedom. Later Jack ended up destroying all the crystals except for the blue one so that all the merfolk were free except for Morveren and her two mermaid friends. Jack left Tonra in charge of the merfolk while he was gone.