Related Clues:

• Thrash
• 'The Lord of the Rings' creature
• Aquatic mammal
• Killer whale
• Miltonian sea creature
• Tolkien creature
• See 64-Across
• Mythical monster
• See 25-Across
• Oil source
• Ogre
• Monster
• Moby-Dick, for one
• Humpback, e.g.
• Tolkien cannibal