Shishizaru, known in Japanese as 獅子猿, is a major boss character in Sekiro: Shadows Die Twice. It is a giant, ape-like guardian beast encountered in the Sunken Valley and later in a more dangerous form. The creature plays a key role as one of the game’s memorable supernatural enemies, tied to the strange, unsettling nature of the world and its hidden lore. It is not a human character with a typical given and family name, but rather a named monster and boss.