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

Dried Bat Blood

NPC	Level	Zone	Chance
Vampiric Duskbat	8 - 9	Tirisfal Glades	17.8%
Ressan the Needler Rare	11	Tirisfal Glades	9.91%
Greater Duskbat	6 - 7	Tirisfal Glades	9.78%