Possible Clues:

• Article taking stance about author
• "__ & Son": "The Bullwinkle Show" feature involving morality tales
• To whom the mouse and the lion pose a problem
• Classical subject of a Velázquez painting in the Prado
• Whence the phrase 'sour grapes'
• Ancient Greek author still widely read by kids
• Author of many a talking animal story
• He wrote a work about French art
• Story-telling slave
• Fabulous man, a 24 dn on the up