Vernon Jones (1912)
150. THE FLY AND THE DRAUGHT-MULE
A Fly sat on one of the shafts of a cart and said to the Mule who was pulling it, "How slow you are! Do mend your pace, or I shall have to use my sting as a goad." The Mule was not in the least disturbed. "Behind me, in the cart," said he, "sits my master. He holds the reins, and flicks me with his whip, and him I obey, but I don't want any of your impertinence. _I_ know when I may dawdle and when I may not."
Aesop's Fables: A New Translation by V.S. Vernon Jones with illustrations by Arthur Rackham (1912). This book is available online at Project Gutenberg.