Æsop. (Sixth century B.C.) Fables. The Harvard Classics. 190914.
The Ass in the Lions Skin
AN ASS once found a Lions skin which the hunters had left out in the sun to dry. He put it on and went towards his native village. All fled at his approach, both men and animals, and he was a proud Ass that day. In his delight he lifted up his voice and brayed, but then every one knew him, and his owner came up and gave him a sound cudgelling for the fright he had caused. And shortly afterwards a Fox came up to him and said: Ah, I knew you by your voice.
FINE CLOTHES MAY DISGUISE, BUT SILLY WORDS WILL DISCLOSE A FOOL.