Hero of the Frostwolf

Speak with Voggah Deathgrip

How does it feel, ? How does it feel to crush your enemies and watch their lines break apart? It feels good, doesn't it?

You should be rewarded for this heroic deed, soldier.

The Alliance have a quest chain along similar lines, The Battle of Alterac, to kill the Horde general. Their quest leads to Hero of the Stormpike, yielding the same choice of weapon rewards as given to the Horde.

In essence, this quest chain requires you to win AV. You should pick up The Battle for Alterac quest before you head into the battleground for the first time.