Minecraft wiki entry for Mule, associated text: Mules are the offspring of horses and donkeys and are closer to (but not quite) the size of a normal horse. Their ears, coats, and manes are like those of a donkey, though mules' coats are darker and reddish-brown. Like donkeys, mules cannot be equipped with armor but can be equipped with chests. Mules cannot have foals, much like mules in real life.