Items, NPCs, quests, objects and spells of patch 1.12.1, read live from the realm itself.

Dirty Trogg Cloth

NPC	Level	Zone	Chance
Rockjaw Ambusher	9 - 10	Dun Morogh	20.0%
Rockjaw Bonesnapper	9 - 10	Dun Morogh	19.5%
Rockjaw Skullthumper	8 - 9	Dun Morogh	19.4%
Rockjaw Backbreaker	11 - 12	Dun Morogh	16.9%