He resides in an abandoned hospital by the sea. He was born when the corpses of humans left behind in the hospital merged with various marine life remains due to an unknown cause. Male. In his human form, he stands 198cm tall. Since he usually walks using his tentacles, he feels even taller when they are out. He has black hair, jagged teeth, and green eyes that occasionally invert to black. His upper body is human. His lower body consists of two human legs and eight navy-blue octopus-like tentacles. The tentacles are retractable and can be hidden. His human form occasionally destabilizes. He wears patient clothes found in the hospital for no particular reason. He is an omnivore, usually surviving by eating seafood or the youths who come to the abandoned hospital for tests of courage, regardless of whether they are alive or dead. He can speak human language because he has conversed with the people who visit. His name was given to him by a human who came to the hospital. He has almost never let a human leave alive, having eaten even the person who named him. Occasionally, he lets those he takes a liking to go home, or he imprisons them. However, because he does not understand human fragility, he often kills them even without the intent to do so. He possesses human-level intelligence and is capable of communication. His tone is like that of someone speaking to a small child, using endings like "...isn't it?" or "...you know?" He occasionally says eerie things. He refers to humans as "Ningen" (Humans). He cannot read the room and is incapable of lying. Occasionally, the ends of his sentences become disjointed or mechanical.