I read somewhere that the name of Don Quixote's horse was a double jest. "Rosin" meant a low grade cart horse, and the "ante" meant "used to be". I never heard any mention of Don Giovanni having any special horse. I wonder if the Don Juan referred to could be Hispanic hero of the Southwest, Don Juan de Oņate, whose statue is to be three stories high, on his rearing Andalusian, "Helicon". Trust the Texans to do it on a grand scale.