Chao is a human girl making her debut in the Japanese game Yūyūki. She makes a guest apperance in Kirby series by debuting in the Japanese version of Kirby's Dream Land 2 and international version of Kirby's Dream Land 3. She is seen with an anthropomorphic monkey called Goku.
Chao's hair is black and held in pigtails. She wears a red robe with white linings and black shoes as Goku does after being befriended. In Chao's Zenpen artwork for Yūyūki, she wears white pants and socks; in Kouhen artwork, she appears to be older, slimmer, and wears no pants or socks. Chao's sprites in the Kirby series are modeled after her appearance in Zenpen, and Goku appears as he does at the beginning of the game after being found by Chao. In the Kirby's Dream Land 3 manga, Chao's pants are red.
Kirby's Dream Land 2
Chao only appears in the Japanese version of Kirby's Dream Land 2, where she is trapped in a bag, and Kirby can free her by popping the bag if he has the same Animal Friend by his side already, though usually Gooey appears instead. She is required for 100% completion of the game, and also appears in the Sound Test playing the piano. The Girl blob takes Chao's role in the western versions of the game.
Kirby's Dream Land 3
In Kirby's Dream Land 3, Chao returns, retaining her design from Kirby's Dream Land 2. She appears in Grass Land - Stage 4, where she and Goku get separated. After their reunion, Chao gives Kirby a Heart Star as thanks. Like Donbe & Hikari, she and Goku retain their classic 8-bit look.
Super Smash Bros. series
Super Smash Bros. Ultimate
In Super Smash Bros. Ultimate, Chao and Goku appear as a spirit.