Milk, also called Chao, is a character that appears in the Nintendo DS version of Sonic Colors. He is a Chao who ended up in Dr. Eggman's Incredible Interstellar Amusement Park and got entangled in the affairs there.
Ending up in Dr. Eggman's Incredible Interstellar Amusement Park, Milk would be chased by Orbot and Cubot, who mistook him for a Wisp. However, he was saved by Sonic and was in deep gratitude to the hedgehog. Later, Milk met Cream and Cheese, where they were being chased by Cubot again. After Sonic saved them, Cream noticed their new Chao friend did not have a name. Tails suggested they called him "Tornado," but when the Chao did not like the name, Cream suggested calling him "Milk," a name the Chao approved of.