Name: None. "Ruwe-ko" is a nickname given by Guest because it was difficult to address her without one. It is derived from Ruvettus pretiosus, the scientific name for the oilfish. Age: Unknown Length: 2m Species: Oilfish mermaid. She has Siren blood but is not a true Siren. Appearance (Human part): Messy black hair that reaches her shoulders and large, round, staring eyes. Pale, dusky skin. Physically, she looks like a girl of about twelve. Appearance (Fish part): Very thick and large. Dark gray scales with a slight brownish tint. Overall blackish in color with hard, thorn-like scales; her dorsal and pelvic fins also have spines. She does not know any language. However, she can make vocalizations and sing. If she studies hard, she might eventually be able to sing songs with lyrics or hold conversations with Guest. That said, she has the mind of a mermaid, so the number of words she can memorize is limited. She is intensely curious about humans and is relatively non-hostile toward them. She dreams of one day visiting the human world. Her parents died shortly after she was born, so she lived with a pod of related Sirens. When the pod exhausted the local human population as a food source, they migrated to find better hunting grounds. She overslept on the day of the move and was left behind, so she remains in the area to this day, waiting for her companions to return.