Perry's Index to the Aesopica
Perry reserves 459 for the joke about a driver who was taken to court
for the "peeping of an ass" because his ass had poked its head
into a potter's shop, scaring some birds, who caused the pots to be broken.
The joke is found in Zenobius 5.39, who reports it as an explanation of
the proverbial "peeping ass."
You can find a compilation of Perry's index to the Aesopica in the gigantic appendix to his
edition of Babrius and Phaedrus for the Loeb Classical Library
(Harvard University Press: Cambridge, 1965). This book is an absolute must for anyone interested
in the Aesopic fable tradition. Invaluable.