The Great Dog Demon was a formidable yokai lord who governed the Western Lands and was renowned throughout Japan. He was never officially named but fathered two sons with different mothers: Sesshomaru, from his consort, an unnamed dog demoness, and InuYasha, from a human woman (unnamed in the manga but called "Izayoi" in the third movie). The Great Dog Demon is first introduced in chapter 12 of the manga as InuYasha's father, described as "a demon dog that roamed the western lands."
In the manga, the Great Dog Demon's primary adversary was the dragon Ryuukotsusei. Although he couldn't kill Ryuukotsusei, he managed to seal him onto a cliff face using his claw. Myouga refers to this battle as the "cause" of his death.
The entrance to his tomb is concealed within a black pearl—a mystical gem that creates a pathway between the mortal and spirit worlds—located inside InuYasha's right eye. Within the pearl, their father's body appears as a colossal dog skeleton clad in armor, which Myouga confirms as his true form. Inside this skeletal structure lies the sword Tetsusaiga, forged from one of the Great Dog Demon's own fangs. This cavernous skeleton is protected by a barrier that repels any non-human being with malicious intent towards humans. Consequently, InuYasha inherits the sword instead of Sesshomaru.
