What kind of animal is stubborn?

Mule: mammalian Chiroptera. Commonly known as "mule", it is a hybrid produced by the mating of male donkey and female horse. Big head, big ears, bigger body than a donkey, similar to a horse. The limbs are long and strong, and the hooves are narrow. Physical strength is stronger than donkey, temperament is docile and lively, life expectancy is longer than horse and donkey, disease resistance, endurance and adaptability to the environment are very strong, and it is often used to pull carts and carry loads. Mules are generally infertile.