Possible Clues:

• Berkeley Breathed's cartoon penguin
• "Mr. Holland's ___" (1996)
• Symphony, say
• Symphony, e.g.
• Magnum ___ (literary masterpiece)
• Composer's masterwork
• Concerto, e.g.
• Magnum ___ (major work)
• "Mr. Holland's ___" (Richard Dreyfuss film)
• Mr. Holland's creation