Perry's Index to the Aesopica
Fables exist in many versions; here is one version in English:
THE SHEPHERD AND THE WOLF CUBS
A shepherd found some wolf cubs and he brought them up, thinking that the fully
grown wolves would both guard his flock and steal other people's sheep to bring
back to his sheepfold. But when the cubs grew up, the first thing they did was
to destroy the man's own flock. The man groaned and said, 'It serves me right!
Why didn't I kill them when they were little?'
The story shows that when people harbor a criminal they become his first
victims without even realizing it.
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 209: Gibbs (Oxford) 34 [English]
Perry 209: Chambry 313 [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.