Possible Clues:

• Killer whale in poor condition
• Creature that stabs Frodo
• Mordor monster
• Sea-monster angry about losing ship
• Cetacean
• 'Lord of the Rings' fiend
• "The Lord of the Rings" enemy
• Imaginary creature coming in for criticism
• 'Lord of the Rings' menace
• Fabled monster in English literature