I have noticed that in Brawl that one of the Challenges is "Clear Boss Battles on Intense" which is obviously very insane of a task. When I go to use one of my four Golden Hammers on the box, it refuses to open. Is this intentional on Nintendo's part? And what trophy does the player earn by clearing Boss Battles on Intense difficulty?

Uh....gamefaqs?

You get the Galleom trophy for clearing that. IIRC none of the Boss Battles or Intense challenges can be broken anyway.

For this one, you'll need to practice fighting them and learn to prioritize dodging their attacks over dealing damage. Think Event 50 in Melee, and dodge everything. Charizard's Rock Smash (fwd-B) is one of the best attacks for damaging. There's also Metaknight's aerial neutral A, DK's down B and Ice Climbers' aerial down B.

Actually, I foolishly used one of my hammers on "Clear All-Star on Intense" thinking it would be difficult. But I wisely used several continues on Classic on Intense, which I realized would have been a wise alternative to using a hammer on All-Star. Thanks for the info! I shall beat Intense Boss Battles with Meta Knight.

Boss Mode is so hard!

Thank you for that informative and helpful post.