Chao are small, cute, blue, teardrop-shaped creatures that appear in the Sonic the Hedgehog series. They are usually found in Chao Gardens and can be raised, fed, and trained by characters like Sonic and his friends. Chao play a supportive role rather than a combat role, serving as collectible,育成-style companions and a major side feature in several games. They are closely associated with the series’ lighter, more playful side, and some can evolve into different forms depending on how they are treated.