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

Prairie Wolf Heart

NPC	Level	Zone	Chance
Prairie Wolf	5 - 6	Mulgore	20.0%
Prairie Stalker	7 - 8	Mulgore	20.0%
Prairie Wolf Alpha	9 - 10	Mulgore	20.0%