umibōzu; sea yōkai; sea monster
A Japanese mythological sea creature, often depicted as a giant black humanoid figure with a bald head, said to appear suddenly and capsize boats.
The umibōzu is a yōkai said to sink ships.
There is an old tale about a fisherman who encountered an umibōzu.
green turtle
A zoological term for the green sea turtle (Chelonia mydas). Also called 青海亀 (あおうみがめ).
See also: アオウミガメ (あおうみがめ)
The green turtle is also called aoumi-game.