Perry's Index to the Aesopica
Fables exist in many versions; here is one version in English:
THE FOX AND THE HYENA
They say that hyenas change their nature every year, so that sometimes they
are male and sometimes female. So when a hyena saw a fox and criticized her
for having spurned her friendly overtures, the fox replied, 'Don't blame me!
Blame your own nature, which makes it impossible for me to tell whether you
would be my girlfriend or my boyfriend!'
This is a story for an ambiguous person.
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 242: Gibbs (Oxford) 365 [English]
Perry 242: Chambry 341 [Greek]
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.