Moop is a moon spirit originating from the Fountain of Sky in the Land of Fountains. Alongside wind spirit Foop, Moop first appears when the Kiryuu sisters Michiru and Kaoru rescue them from a falling tree at the Fountain of Sky, establishing an early connection. Moop ends sentences with "-mupu" and primarily serves as a power source for the Pretty Cure warriors' enhanced transformations.

Moop and Foop supply their lunar and wind powers through the Spiral Ring Set, enabling Cure Bloom and Cure Egret to perform the Spiral Heart Splash attack. After Flappy and Choppy are captured and injured, Moop and Foop's healing powers facilitate an upgrade from the Mix Commune to the Crystal Commune. This advancement allows the Pretty Cure duo to harness moon and wind powers, leading to new forms: Cure Bright (utilizing lunar energy) and Cure Windy (utilizing wind energy). Moop's lunar power specifically fuels Cure Bright's abilities, including energy beam attacks and enhanced combat capabilities.

In the film *Tick Tack Kiki Iippatsu!*, Moop accompanies Saki and Mai during an incident in the Land of Clocks. When the duo faces internal conflict after inadvertently aiding antagonist Sirloin, Moop assists them in navigating an endless maze. He provides support as they resolve their disagreement and confront Sirloin, who aims to freeze time by halting the Eternal Clock, aiding the warriors in overcoming temporal disruptions and restoring time's flow.

Throughout all appearances, Moop maintains a quiet, observant demeanor. His powers are intrinsically linked to lunar energy, manifesting in Cure Bright's techniques and the narrative's theme of natural elements. Moop's background and development emphasize his function as a guardian of cosmic balance and a catalyst for the warriors' evolution.