Dokin-chan operates as Baikinman's primary partner and frequent secondary antagonist in various schemes. She appears as an orange-red germ-like entity with green eyes, a single antenna, a long tail, pink shoes, and white hands. Her facial area is predominantly white, featuring a continuous orange hue extending to her nose and small red cheeks.

Personality-wise, she exhibits selfishness, demanding behavior, and greed, often bossing Baikinman around to satisfy cravings for food, objects, or people. She tends to flee unfavorable confrontations. Despite these traits, an underlying kindness surfaces through her intense affection for Shokupanman, driving extreme efforts to capture his attention—maintaining a room filled with his posters and plush toys while frequently daydreaming about their imagined relationship. She firmly believes herself the world's cutest individual.

Relationships significantly shape her character. She shares a complex dynamic with Baikinman, treating him rudely while assigning errands yet harboring genuine care beneath the surface. With her younger sister Kokin-chan, she engages in typical sibling conflicts intensified by their rivalry for Shokupanman’s affection. Beyond these bonds, Dokin-chan shows little concern for others' suffering unless Shokupanman is threatened, actively preventing Baikinman from harming him.

Her equipment includes a specialized staff with one end enlarging objects and the other reducing them, though its usage waned over time. She also pilots a pink UFO with yellow-tipped appendages, typically employed for non-combat tasks like transporting baskets or flowers but occasionally used to hold hostages during Baikinman’s schemes.

Her earliest official appearance occurs in the 1975 picture book *Anpanman and Dokin-chan*. Across all subsequent media—seasons, movies, and spin-offs—her core characteristics and role remain consistently portrayed.