An Octupus man located in Atlantis.
To get to him, you will need the Boy (or alternatively, the Chainsaw) and the Fairy or the Child effect. Interact with the Black Twin in the Theatre, then use the Boy effect to chase her away (talking to her causes her to switch places with you, allowing you access to the door). Enter the door, and interact with the piano. Then move up, and equip the Fairy or the Child effect to be able to go through the small opening. You will then, be in Atlantis.
Stroll around for a bit, and you should be able to find him. If you use the Fairy effect on him, he will become frightened and reveal his tentacles and large eye. Doing so, will also unlock a Wallpaper.
By interacting with him from a direction opposite the one he's facing, he will turn and look at you, and stare at you for a moment before continuing to walk around.
Tako Otoko, tends to be a rather lonely guy, and as mentioned above; seems to hate Fairies for some reason. He is rather silent, but can be rather tricky and mischievious sometimes ... just like Yukata, in a way. He can probably be as pervertic, as well from what fan depicted of him.
It is believed that he oftenly strolls around Atlantis to look for 'treasures' (from the surface) that may seem valuable and interesting to him, before taking the abnadoned item.
It is unknown on why he is afraid of fairies, though.
Other than that, from what fans depicted; he seems to be rather close to Aoshiru, and Gakuran.