Possible Clues:

• Morse: character associated with Lewis
• Animal in a Beatles title
• Carpenter's pal, in rhyme
• Are you in the laws with a carpenter?
• Morse, perhaps, involving Lewis at first in fight over us
• Aquatic, web-footed, carnivorous mammal
• Parts of marine mammal found in Russia and Wales
• Whiskery beast was outside front of local before game
• The ___ and the Carpenter (Lewis Carroll poem)
• Ungainly creature observed holding page locator up