Mermaid

Mermaid (人魚) is a high-ranking supernatural in the Jibaku Shounen Hanako-kun series. She is able to manifest in Kamome Academy while living underwater with other fish, although it is unclear whether that place is bound to the school.

Appearance
She appears to be a giant fish with humanoid features, such as long messy hair decorated with barnacles and sharp teeth. Her fins are long and end in claws.

Personality
Because of her high ranking as a supernatural and old age, she thinks highly of herself. She speaks in a regal tone and regards the School Wonders as mere apparitions. This is shown in her encounter with Hanako, a supernatural who was born in only the last recent decades. She is quick to dismiss him, caring only about retrieving her new servant.

It is later revealed that she is actually very kind and caring towards her subordinates.

Great Mermaid's Life Blood
By drinking the Mermaid's Life Blood, previous bonds with other supernaturals can be over-written, and the individual will become bound by fate to the Mermaid instead.

Trivia

 * The Mermaid is probably based on the Ningyo, a fish-like creature from Japanese folklore.