Possible Clues:

• Specialist M.D.
• Tolkien tree
• Adjective suffix
• ''Lord of the Rings'' creature
• Rhinitis diagnoser, for short
• ''The Lord of the Rings'' creature
• Dr. who handles otitis cases: Abbr.
• Treebeard of 'The Lord of the Rings,' for one
• Treebeard in 'The Lord of the Rings,' e.g.
• "The Lord of the Rings" creature