Chao are small, cute, and mysterious creatures that appear throughout the Sonic the Hedgehog series. Not a single character, but rather a species, Chao are known for their childlike innocence and adaptability. Players can raise and interact with them in the Chao Garden minigame, where Chao can evolve and develop based on player actions. Though they do not play a major narrative role, Chao are beloved mascots and often serve as side characters, adding a nurturing and interactive element to the games.