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

Pristine Crawler Leg

NPC Level Zone Chance

Silt Crawler 40 - 41 Swamp of Sorrows 80.0%

Monstrous Crawler 43 - 44 Swamp of Sorrows 80.0%
Quest Level Side

... and Bugs 40 Both

NPC	Level	Zone	Chance
Silt Crawler	40 - 41	Swamp of Sorrows	80.0%
Monstrous Crawler	43 - 44	Swamp of Sorrows	80.0%