THE ASS IN THE LION'S SKIN 
The Ass once dressed himself in the Lion's skin and went about frightening all the little beasts. Now he happened on the Fox, and tried to frighten him too; but the Fox chanced to hear him speak, and said: "Well, to be sure, I should have been frightened too, if I hadn't heard you bray, and seen your ears sticking out."
So there are some men who make themselves appear very fine outwardly, but are betrayed as soon as they begin to talk.