Perry's Index to the Aesopica
Fables exist in many versions; here is one version in English:
THE BIRDS AND THE CUCKOO
Aesop says that when the cuckoo asked the little birds why they ran away from
him, they said it was because he would someday turn into a hawk.
Aesop's Fables. A new translation by Laura
Oxford University Press (World's Classics): Oxford, 2002.
cover, with new ISBN, published in 2008; contents of book unchanged.
Perry 446: Gibbs (Oxford) 300 [English]
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.