Possible Clues:

• He would have nothing to do with 18 down with his claws, by the sound of it
• ''Little old driver'' of a familiar verse
• Annual fly-by-nighter
• 12/24 visitor
• Seasonal cookie eater
• See 5-Down
• Clement Moore's 'right jolly old elf'
• In verse, 'His cheeks were like roses, his nose like a cherry!'
• Annual stocking suffer
• He has claws, by the sound of it, but not like 11 across