The clerk gives him the rooster and tells him that they call roosters cocks around here and that you should pull their head when they get noisy.
The man says O. K and asks for a donkey.
The clerk gives the man the donkey but tells the guy that they call donkeys asses around here and that you scratch them when they get noisy.
The man says fine and stars walking home.
Half way there the animals get real noisy and the man has his hands full. So he runs over to two people walking by and says "Quick hold my cock and pull it while I scratch my ass."