In Japanese mythology, an inugami ("dog god") resembling, and usually originating from, a dog, (although other similar species are interpreted as being. e.g., wolves, raccoons, and weasels.) and most commonly carrying out vengeance or acting as guardians on behalf of their "inugami owner." Inugami are extremely powerful and capable of existing independently, (without master or possession) as well as turning on their "owners" and even possessing humans. Even so, while Inugami can betray their masters, they may also be the loyalest of companions.
"Dogs of Japanese legend who possess human bodies. When a person is possessed by an Inugami, he feels pain in his chest, hands, and feet and begins to bark like a dog. People with strong or unstable emotions are thought to be particularly susceptible to being possessed. Inugami are said to originate from the islands of Kyushu and Shikoku. They were sometimes used as objects by Japanese diviners. Since Inugami will not leave a family once they possess it, it was once customary when arranging marriages to check whether the family had an Inugami."
—Shin Megami Tensei IMAGINE compendium
Inugami can be contracted in the Suginami field and are one of the targets of the earlier acts, where players are asked to fuse an Erthys to take advantage of their weakness. They appear regularly within Suginami Tunnels' gold instance and within Shibuya's Quartz instance, where they appear as more powerful variations. The variation in Quartz's gold-level instance will regularly use all four elemental drain area of effect buffs.
Inugami appears in the "Hunter Tournament Prelims" Challenge Quest while supporting Flynn's first opponent, Subzero Nodon. It can later be found as a normal enemy in Ikebukuro. Inugami can teach Flynn the Fire Breath and Rakunda skills through its Demon Whisper.
Inugami appears as an optional boss in Dark Tsukudo-Cho, where he says he is born not of mother and father, but hatred. After his defeat, he says he does not want to disappear and so asks Raidou to make him his demon. Depending on the choice he will wish to be reborn as a demon that brings happiness to others if he is allowed to die, while he joins Raidou if he wants to have him. Afterwards, Astaroth appears after enjoying the fight.
"A dog spirit said to possess people in Japanese lore. Those possessed are put in a state of "inu-tsuki," and lose consciousness. There tends to be more lore about the Inugami in areas where the fox, which is an animal in folklore that is treated in a similar manner, is not common. Onmyoji used them as familiars."