Myriam Moonsinger is a level 35 quest giver located on a hill just south of the huge pig skull-shaped entrance to Razorfen Downs[49.0, 94.9] in the Horde-aligned territory of the Barrens. She is outside the instance, and friendly to both Alliance and Horde.
She starts the quest  (Dungeon). Contrary to the quest designation, however, the mobs needed are non-elites found entirely outside the instance, in the village around her.
See List of the Barrens NPCs.