Perry's Index to the Aesopica
Fables exist in many versions; here is one version in English:
War broke out between all the beasts and the birds. When the ostrich was captured,
she fooled both sides by being both a bird and a beast: she showed the birds
her head, and the beasts her feet.
You cannot trust a two-faced associate.
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 418: Gibbs (Oxford) 362 [English]
Perry 418: L'Estrange 42 [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.