In Japanese mythology, those who became Tengu and had ignorant or cruel hearts would become ko-tengu (small tengu) and those that were knowledgeable would become dai-tengu (big tengu). The koppa-tengu or "leaf Tengu" are among the smallest of the kotengu family, possessing very little spiritual energy. It is sometimes said wolves that live an exceptionally long life will become koppa-tengu and later will change into a form closer to a Karasu Tengu. The koppa-tengu often act as retainers and messengers to larger tengu, especially the Tengu King: Sojobo, a Kurama Tengu.
"A type of Tengu, the supernatural form of a wolf that has lived to an extraordinary age. Like Karasu-Tengu, they appear as mountain priests and act as menial servants to other Tengu. Unlike Anba-Tengu and Karasu-Tengu, Koppa-Tengu have no great supernatural powers, but their huge wings allow them to soar freely through the sky. They are clever but cowardly, rarely appearing before humans and traveling silently in groups at night. Among the many different types of Tengu, Koppa-Tengu serve as the messengers. They use the elements of small birds for this purpose."
—Shin Megami Tensei IMAGINE compendium
Koppa-Tengu can be contracted in Shibuya's Celu Tower bronze instance and Ichigaya Camp's bronze instance.
The terminal guardian in Ueno summons two Koppa Tengu and a Karasu Tengu when Flynn and company attempt to enter the Terminal and stumble right into the Domain that has been set up. The Koppa Tengu will act as support for the Karasu Tengu.
Koppa Tengu will later appear as a regular enemy in the western areas of Shinjuku. He can teach Flynn the Zanma, Sukukaja and Bad Company skills through his Demon Whisper. Koppa Tengu can evolve into Karasu Tengu upon reaching level 22. Together, Koppa Tengu and Karasu Tengu are used in a special fusion in order to summon Kurama Tengu.
Koppa Tengu can be found within Kanda-no-yashiro. He can teach the Sukukaja, Zanma and Bad Company skills through his Demon Whisper. Koppa Tengu benefits from learning Force and support skills. Koppa Tengu will evolve into Karasu Tengu at level 20 provided that Nanashi is able to control it.
"A type of Tengu that dwells in the deepest forests. Their spiritual power is weaker than other tengu, which make them smaller in stature. When the time comes, long-lived wolves transform into this form that closely resembles the Karasu Tengu."