"The Boy Who Cried Wolf" is one of Aesop's Fables, numbered 210 in the Perry Index. From it is derived the English idiom "to cry wolf", defined as "to give a false alarm".

The tale concerns a shepherd boy who repeatedly tricks nearby villagers into thinking a wolf is attacking his town's flock. When a wolf actually does appear and the boy again calls for help, the villagers believe that it is another false alarm and the sheep are eaten by the wolf. In a later English-language poetic version of the fable, the wolf also eats the boy.

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