Matchlock Eagle commands the Eagle Team in the world-domination-seeking Secret Society Gekko. Surgical remodeling fused his body with eagle traits, transforming him into a monster commander whose appearance reflects this avian fusion, including white hair and a large, eagle-like form. Associates note his tendencies toward self-aggrandizement.

As a high-ranking monster leader, he directly oversees Heat Princess, who hides her identity from other Gekko members. He actively participates in strategic organizational meetings, such as selecting attack targets. When Supreme Leader Bosslar promoted Reaper Princess to monster status, Matchlock Eagle enthusiastically endorsed the superiority of monster bodies. He displayed visible shock when Bosslar dismissed animal-based enhancements as a weakness and supported Reaper Princess's decision to decline the transformation.

In combat, he wields a personal matchlock weapon carried on his back. During Gekko's deployment of the Ultimate Phantom—a creation intended to fulfill their destructive goals—Matchlock Eagle coordinated with fellow commanders to confront the entity. Their collective efforts failed, resulting in the base's destruction. From the ruins, he witnessed Red Gelato and Reaper Princess successfully subdue the Ultimate Phantom via televised broadcast.