linguistic:paraphrasing
Characteristics

In general terms, in both the mule and the hinny, the foreparts and head of the animal are similar to those of the father sire, while the hindparts and tail tend to resemble those of the dam. A mule is generally larger than a hinny, with longer ears and a heavier head; the tail is usually covered with long hair like that of its mare mother. A mule has the thin limbs, small narrow hooves and short mane of the donkey, while its height, the shape of the neck and body, and the uniformity of its coat and teeth are more similar to those of the horse.

Mules vary widely in size, from small miniature mules under 125 cm (50 in) to large and powerful draught mules standing up to 180 cm (70 in) at the withers. The median weight range is between about 370 and 460 kg (820 and 1000 lb).

The coat may be of any color seen in the horse or in the donkey. Mules usually display the light points commonly seen in donkeys: pale or mealy areas on the belly and the insides of the thighs, on the muzzle, and around the eyes. They often have primitive markings such as dorsal stripe, shoulder stripe or zebra stripes on the legs.

The mule exhibits hybrid vigor. Charles Darwin wrote: "The mule always appears to me a most surprising animal. That a hybrid should possess more reason, memory, obstinacy, social affection, powers of muscular endurance, and length of life, than either of its parents, seems to indicate that art has here outdone nature".

The mule inherits from the donkey the traits of intelligence, sure-footedness, toughness, endurance, disposition, and natural cautiousness. From the horse it inherits speed, conformation, and agility. Mules are reputed to exhibit a higher cognitive intelligence than their parent species, but robust scientific evidence to back up these claims is lacking. Preliminary data exist from at least two evidence-based studies, but they rely on a limited set of specialized cognitive tests and a small number of subjects. Mules are generally taller at the shoulder than donkeys and have better endurance than horses, although a lower top speed.

In the early twentieth century the mule was preferred to the horse as a pack animal – its skin is harder and less sensitive than that of a horse, and it is better able to bear heavy weights.