4x42 - The Bullwinkle Show

Esmerelda Fump is the ugly maid at the palace- but she finds that if she gets to sleep, she gets prettier and prettier. Seeing her in her "pretty" state, the prince wants to marry her, but she keeps having to go take a nap to avoid looking ugly. Finally, the prince calls the court wizard and asks him to make her into a "night owl"- which he does... literally!