Det är nog en Ningyo .
Från den länkade Wikipedia-artikeln:
Ningyo (人魚, "human fish", often translated as "mermaid") is a fish-like creature from Japanese folklore. Anciently, it was described with a monkey’s mouth with small teeth like a fish’s, shining golden scales, and a quiet voice like a skylark or a flute. Its flesh is pleasant-tasting, and anyone who eats it will attain remarkable longevity. However, catching a ningyo was believed to bring storms and misfortune, so fishermen who caught these creatures were said to throw them back into the sea. A ningyo washed onto the beach was an omen of war or calamity.