The Fairy Stars' design differs depending on its upgrades, most of which are seen in Kingdom Hearts Union χ. It is modeled after Flora, Fauna, and Merryweather, sporting their respective color schemes.
The default Fairy Stars consists of a thin, red bar that serves as the handle and the blade. The guard consists of two curves, one blue and one green, that curve near the base of the handle. Two yellow stars decorate the base of the blade, with a large, bronze, four-pointed star connected to the end of the main blade. The teeth consist of a single red star. The Keychain has a series of yellow and grey links, and the token is Flora, Fauna, and Merryweather's hats stacked together.
Its first upgrade, also seen in Kingdom Hearts Birth by Sleep, has the blue and green guards extend to become part of the blade while the red rod fades to gold. The star in the blade's base is brighter and has two fairy wings. The guard now has two stars at the base. The blade's tip is now a golden, eight-pointed star, with three of its points extending into another three stars - one green, one red, and one blue - acting as the teeth. The Keychain's links are silver and decorated with golden stars, and on the token, Flora's hat now sports golden wings.
Its second upgrade majorly redesigns the Keyblade as a whole, representing Maleficent (who is also a fairy) along with the other three fairies. The center rod fades from red to black past the hilt, and the blue and green rods wrap around the center rod in a helix-shaped formation, culminating at the halfway point of the keyblade into a small star, from which two clouds extend along with the center rod up to the star at the tip of the blade. The eight-pointed star has two black concentric circles behind it, and the three stars on the teeth - now all golden - have a clockwise black trail behind them. The Keychain is a yellow string decorated with golden stars. Merryweather's hat is slightly taller on the token.
Its third upgrade wraps the Keyblade in a golden aura, with lens flares periodically appearing along it.
The Fairy Stars' name is a reference to Flora, Fauna, and Merryweather, the three good fairies from the Enchanted Dominion. "Star" reflects the numerous stars worked into the Keyblade's design, which are in turn a reference to the sparkles that Flora, Fauna, and Merryweather's magic generate.