The Yagi Inves is an Advanced Inves and antagonist in Kamen Rider Gaim.
A Yagi Inves emerged in Zawame City and began attacking people until Armored Rider Gaim and Jiro fought it and drove it off. The Yagi Inves later returned and fought alongside Ryoma-Hakaider against Gaim Kachidoki Arms and Kikaider, only to be destroyed after Hakaider fled when Gaim and Kikaider performed a combined finisher on it.
A Yagi Inves later appeared as part of Redyue's Inves army sent as a vanguard for the Overlord invasion of Zawame. The Inves invasion was met with opposition from the Armored Riders, with the Yagi Inves being destroyed by Armored Rider Bravo.
Several Yagi Inves were part of a group Inves led by Grinsha to capture humans in Zawame to be used to power a machine Redyue constructed to revive the Overlord Queen for Rosyuo as part of his plot to gain the Forbidden Fruit. One of these Yagi Inves was destroyed alongside several other Inves by Gridon Suika Arms (Odama Mode).
A Yagi Inves later appeared as part of the group of Inves destroyed by Gaim's Daidai Ittou in the infested Zawame right before his encounter with Lapis.
After Kaito Kumon evolved into Lord Baron, a Yagi Inves and a Lion Inves appeared to worship him as he declared his intention destroy the world and remake it in his image to the Armored Riders. When Bravo and Gridon stood up to him, the two Inves and Marika fought them and defeated them.
Several Yagi Inves appeared as part of both Kaito Kumon and Kouta Kazuraba's Inves army, which they summoned with their newfound Overlord powers.
- Yagi Inves's costume is a modified version of the Komori Inves costume.