Moop is a small, legless green fairy linked to the moon, possessing large round ears and emerald eyes. A red orb tips his tail, while a yellow ball marked with a small heart adorns his forehead. He originated alongside Foop from the Fountain of Sky. Moop can grant power upgrades and provide new items for techniques. His personality blends playfulness, childishness, and shyness, often punctuating his sentences with "-mupu".

He shares an inseparable bond with Foop. After the Kiryuu sisters, Michiru and Kaoru, rescued them from a falling tree at the Fountain of Sky, both fairies developed a connection to the sisters; Moop exhibits a closer link to Michiru specifically. He and Foop firmly believe in the inherent goodness of the Kiryuu sisters. Following this rescue, Moop and Foop observed Hyuuga Saki and Mishou Mai before deciding to live with Saki. Their mischief often leads them to wander away from their companions, creating difficulties for Saki and Mai. Moop channels his power through Flappy, enabling Saki to transform into Cure Bright. He also appears aware of Flappy's feelings towards Choppy.