Larval Acid

Larval Acid is a corrosive liquid that is used by some carrion creatures to help digest their food.

Source
This item drops from Carrion Devourers and Carrion Grubs in the Eastern Plaguelands, and Silicate Feeders in Ruins of Ahn'Qiraj.

Leatherworking

 * Bramblewood Boots
 * Hide of the Wild
 * Sandstalker Bracers
 * Sandstalker Breastplate
 * Sandstalker Gauntlets
 * Swift Flight Bracers

Enchanting

 * Enchant Gloves - Threat (Note: As of patch 2.2, this recipe no longer requires Larval Acid)