Diamond Tough is an earth pony NPC who can be found just northwest of the Crystal Castle. He wears Bronze armor, complete except for the back plate.
- "Don't start trouble, you don't get in trouble."
- "No matter what he things, I do not hate Helping Hoof. I do, however, off the record, hate his little 'who-me?' attitude."
- "Thank Harmony, my shift's nearly over."
- "Nothing to report. That's always a good sign."
- "Off the record, but my CO, Obsidian, is a bit too eager for war. It's called the Age of Harmony for a reason, and me, I like Harmony."
- "You say 'free spirit,' I say 'punk with no sense of responsibility, who's not nearly as witty or important as you think you are, and who needs to get a life."
- As diamond is one of the hardest substances known, the phrase "diamond tough" implies a very resolute pony.