Maruge is a diminutive, rotund yōkai cloaked in dense fur, with short limbs and wide eyes often veiled beneath his shaggy hair. His design shifts subtly across adaptations, transitioning from brown-haired origins in early portrayals to vibrant red or yellow hues in later anime renditions. A concealed mouth atop his skull lets him snap at unsuspecting victims who mistake him for a piggy bank and insert coins.

First appearing in the *Geta Battle* arc of Shonen Magazine, Maruge’s tragic past involves enslavement by Sakabashira, who held his children hostage to coerce him into thievery. Forced to mimic a coin-storing piggy bank, he would abscond once filled, until Fairy Hanako and Kitarō intervened. Captured by Nezumi-Otoko, Maruge later aided Sakabashira by swapping Kitarō’s enchanted geta with counterfeit sandals infused with the villain’s essence. Post-rescue, he exposed the plot and reunited with his family.

Within the *Yōkai Cloth* narrative, Maruge alerted Kitarō to Qi’s fortress and facilitated Medama-Oyaji’s covert infiltration. In the climactic clash, he strategized Nezumi-Otoko’s use of pilfered Cloth Powder to transmute Qi into inert fabric. Though briefly siding against Kitarō in *The Great Yōkai Trial*, Medama-Oyaji’s reminder of Kitarō’s loyalty swayed him back.

Subsequent portrayals cast Maruge as a frequent background figure. The 2018 anime shows him joining GeGeGe Forest’s mob against Agnès before aligning with Kitarō against Backbeard. He resurfaces in the spin-off *USO MAKOTO Yōkai Hyaku Monogatari*, summoned by a shadowy committee to thwart unnamed threats.

Maruge’s skills include hardening his fur into armor and manipulating locks. Rooted in Edo-era lore, his legend warns of finger-biting retribution for those duped by his piggy bank guise. A parallel entity in *Miage-Nyūdō* shares insectoid traits but lacks explicit ties to Maruge.