Related Clues:

• Clark Kent, for one
• Have
• Hyde, to Jekyll
• See 37-Down
• Amigo
• Bruce Wayne, to Batman
• Shadow, so to speak
• 'Be a ___!'
• Bucko
• Cohort
• One of the 'three faces of Eve'
• See 9-Down
• Compadre
• Helping sort
• Blood brother