WoWDB

Bristlemaul is at 38.1, 45.5 in Highmountain. he's inside the cave in Fields of An'she, south from The Witchwood flight point.
He's a part of Adventurer of Highmountain achievement, has a chance to drop  Valiant's Glory,  Thick Bristly Hood.

For TomTom users:
/way Highmountain 38.1, 45.5 Bristlemaul