Melonpanna originates from melon bread animated by the nectar of a flower of love. Her appearance features large green eyes, a small green nose, and three diagonal lines crossing her face. She wears a dark green uniform accented with a light green belt, gloves, and shoes, plus a cape displaying green on top and orange underneath. A cursive "m" insignia adorns both her dress and uniform chest.

Her personality embodies kindness and gentleness; she treats everyone with consistent warmth and care. Though possessing considerable physical strength, she avoids confrontation, reserving her power for necessary defense. She holds deep affection for her older sister Rollpanna, often feeling lonely due to their infrequent meetings. She extends protective, nurturing attention to Creampanda, treating them like a younger sibling.

Her primary ability is the "Melo-Melo Punch," which induces temporary paralysis in adversaries through overwhelming affection or awakens individuals from deep sleep. Her secondary ability, "Melo-Melo Juice," involves extracting droplets of melon juice from her head. This juice reverses the "blackened" condition inflicted by Baikinman on allies, though its effectiveness diminishes significantly if Rollpanna's inherent goodness is compromised or removed. Like others in her group, she uses her cape for flight.

She is vulnerable to fainting when strength-depleted, requiring melon juice for restoration. She also risks losing self-awareness if Rollpanna's malevolent aspects dominate. Within the narrative "Soreike! Anpanman: Inochi no Hoshi no Dolly," she participates in the life-celebrating Star Festival. Her interactions and contributions occur alongside other characters responding to Dolly, an abandoned doll animated by a Star of Life, and the threats from Baikinman's colossal robot.

Her origin traces to her debut in episode 200, titled "Melonpanna is born." While lacking an official birthday, enthusiasts recognize her first appearance date, September 21, 1992, for commemoration.