This mule is by Pisanello, an Italian artist who lived a hundred years before Dürer and Michelangelo. Most of his remarkable drawings were lost until 1836, when a Milanese print-publisher, out of the blue, offered them for sale as works by Leonardo da Vinci. The Louvre of Paris bought them and found that they were by Pisanello.
The mule is so skillfuly drawn—obviously from life—that not only are all its shapes rendered truthfully but even the hair covering them—all with absolute economy of line. And, as if that weren’t enough of an achievement, the animal looks alive and even friendly as it seems to wait for its rider.