A crow, sitting at her ease upon a sheep's back, pecked her with her beak. After she had done this for a long time, the sheep, so patient under injury, remarked: "If you had offered this affront to the dog, you could not have endured his barking." But the crow thus answered the sheep: "I never sit on the neck of one so strong, as I know whom I may provoke; my years having taught me cunning, I am civil to the robust, but insolent to the defenceless. of such a nature have the gods thought fit to create me." 
This fable was written for those base persons who oppress the innocent, and fear to annoy the bold. 