Kill 12 Galak Scouts, 10 Galak Wranglers, and 6 Galak Windchasers, and then return to Cliffwatcher Longhorn in Freewind Post.
[player], I entreat you to hunt these centaur down. They shall feel the wrath of our revenge. Attack the centaur camp to the north of Freewind Post! Let wrath guide your hand!