In terms of physical appearance, fairies appear to be short humanoids with translucent, rounded wings, anime-style eyes, and body proportions similar to a small child; most are smaller than even Kirby. Out of them all, the Queen is the tallest, and she is around Adeleine's height. They appear to be an all-female species, and all wear skirts or dresses; individual members are largely distinguished by their hairstyles, hair colors, and accessories. Their design is quite similar to the angel found in Kirby's Dream Land 3 and the People of the Sky found in Kirby: Triple Deluxe, though both are slightly smaller and have less detailed eyes more similar to Kirby's.
The fairies live in peace on Ripple Star under the rule of the Queen, protecting their source of power, the Crystal. However, the Dark Matter force invades the planet, throwing their carefree life into havoc. The Queen panics until she talks with Ribbon, who agrees to flee Ripple Star with the Crystal. She is ambushed en route by Dark Matter forces and the Crystal is split into shards, causing her to crash land onto Pop Star. From here, Ribbon joins forces with Kirby to save her planet. The duo, along with the friends they meet along the way, eventually collect all of the Crystal Shards and defeat Dark Matter, and the fairies are happy once more.
A bunch of fairies appearing in one of the cut-scenes that take place on Ripple Star
Fairies gathered during the ending cut-scene for Kirby 64: The Crystal Shards
Sketch of three fairies from the False Ending credits for Kirby 64: The Crystal Shards