Carlos

Carlos is Lorenzo de' Medici's horse. He apparently pulls to the left so the rider must compensate and pull to the right.

Biography
Leonardo da Vinci asked Lorenzo is he could borrow his horse as part of his plan to help Verrocchio flee Florence. As Lorenzo walked Carlos down the street, he told Leo about him and asked what his plan was but realized Leo did not trust so left him to it. Leo left Carlos by the city gate and, after helping Verrocchio escape from jail, intended for him to reach Carlos and escape. However the plan failed when the guards shut the gates just as Verrocchio arrived. Carlos was then returned to the stables at the Medici Palace. (Perspective)