Dark Iron Herald is an NPC related to the Brewfest event. Every 30 minutes, just outside of Orgrimmar, the Dark Iron Dwarves attack the festival. This individual announces the battle and the result.
No one expects the Dark Iron dwarves!
We did it boys! Now back to the Grim Guzzler and we'll drink to the <number> that were injured!!
RETREAT! We've taken a beating and had <number> casualties! We can't keep taking these losses! FALL BACK!