Any history of Beauty and the Beast I've ever read cites the myth Cupid and Psyche as the earliest literary version of Beauty and the Beast, which was probably itself based on earlier oral tales. Usually the history skips from there to the 1700s in France, but Jerry Griswold mentions another very early version.
The Girl Who Married a Snake is an Indian tale from The Panchatantra, printed in 500 A.D. but "known to have existed in oral form well before its appearance in print." I'm amazed by its similarities to Straparola's "The Pig King" from the 1550s-much more than to Cupid and Psyche, though The Panchatantra and Straparola were one thousand years apart. It is told more from the perspective of the parents of the animal son, not the bride's. The obedient bride is not given a stipulation against looking at her husband, and when the father eventually destroys the snake skin, he frees his son.