Pokonyan is a mysterious cat-raccoon hybrid of unknown origin, often perceived as a magical or lunar cat. He possesses a distinctively cute and whimsical appearance and speaks with a feline verbal tic, ending sentences with "nyan."

His story begins when discovered tucked away among sleeping bags during young Miki Konoha's family camping trip, initially mistaken for a tanuki. From this encounter, he adopts Miki as his sister and becomes her constant companion.

Pokonyan wields potent psychic abilities that manifest children's fantasies into reality. His powers include shapeshifting, altering his size, and generating fantastical gadgets or scenarios, activated by the incantation: "Ponpokopon no, henpokorin no, nyan!" Well-intentioned but impulsive, his magic often spirals into comical near-disasters, fueling adventures centered on fulfilling Miki's wishes.

In the original 1975–1978 manga, Pokonyan resided with a boy named Taro, aiding him through psychic powers and gadgets, emphasizing their brotherly bond and collaborative problem-solving. The 1993–1996 anime adaptation shifted the premise, replacing Taro with Miki as his primary companion while retaining his core traits of mystery, magical prowess, and loyal friendship. This version targeted younger audiences, expanding his role in transforming daily life into fantasy.

He reappeared in the 2016 short film "Pokonyan & Doraemon: Pompokonyan de Kokohore Nyan Nyan!?", marking his first animated appearance in 23 years. Here, he interacted with Doraemon and Nobita, maintaining his established personality and powers, including a storyline featuring Miki's grandfather.

Throughout all appearances, Pokonyan's relationship with his human companions evolves from initial surprise to deep, enduring bonds. His adventures consistently blend heartfelt goodwill with comical mishaps, underscoring themes of friendship and imagination.