Nezumi Otoko takes the form of a rodent-like human-yōkai hybrid in the crossover film *Yo-kai Watch Shadowside: Oni-ō no Fukkatsu*, retaining his role as a cunning trickster from *GeGeGe no Kitarō*. His design showcases prominent whiskers, pronounced buck teeth, and a flowing brown cloak, complemented by sharp claws employed to unsettle adversaries—though the film’s art style mutes his traditionally menacing traits compared to earlier depictions. A longstanding figure in the *GeGeGe no Kitarō* franchise, he originates as a 300-year-old half-human, half-yōkai entity, though this history remains unaddressed in the *Yo-kai Watch* film. Within the movie, he tactically allies with Kitarō’s group yet covertly schemes against them, exemplified by a moment where he devises a scam targeting protagonists pursuing Kitarō’s aid. His signature abilities, including noxious breath and flatulence-based attacks, align with his classic portrayal but remain underutilized in this narrative. In *Yo-kai Watch* lore, Nezumi Otoko holds the classification of a Rank A Yo-kai within the Slippery tribe. He features in the mobile game *Yo-kai Watch: Wibble Wobble* as a limited-time event character during the "Yo-kai Watch vs GeGeGe no Kitaro: Dream Match" tournament, ascending to Rank SS in his "Awoken" form. The film integrates him into the Kitarō Family alongside allies like Neko-Musume and Medama-Oyaji, maintaining his established persona without elaborating on *Yo-kai Watch*-specific origins.