OK, I weakened...this is the oldest known example of the genre, told by a bard at the court of King Arthur ( or was it King Nevil the Ne'erdowell?).
No time to post it all but you'll get the drift from the punchline:"What?" said Sir Lancelot, indignantly refusing to ride the magy wolfhound, "Send a knight out on a dog like that?
RtS