Utai-Gaikotsu (ウタイガイコツ) is a demon in the series.
In Japanese lore, a Utai-gaikotsu is a monster born when the negative energy of a person who was subject to a particularly violent murder possesses the remains of that person's skull. The Utai-gaikotsu then seeks revenge on its killer by making up a song detailing its death, and singing it repeatedly to either drive its killer insane or alert others to what happened to it.
- Shin Megami Tensei IMAGINE: Haunt Race
- Devil Summoner: Raidou Kuzunoha vs. The Soulless Army: Pagan Order
- Devil Summoner: Raidou Kuzunoha vs. King Abaddon: Pagan Order
Shin Megami Tensei IMAGINE
Utai-Gaikotsu was implemented during the 2015 Halloween event. They have an incredibly powerful boost feature for suicide affinity skills.
Devil Summoner: Raidou Kuzunoha vs. The Soulless Army
- "A talking monster born when the negative energy of the one killed possesses a skull. It attempts to revenge itself on its killer by making a song of the details of its death"
- —Devil Summoner: Raidou Kuzunoha vs. The Soulless Army Devil Chart
Devil Summoner: Raidou Kuzunoha vs King Abaddon