Venom
From WikiRaider
Venom are one of the Resources in Shadow of the Tomb Raider. These are obtained by collecting Blister Beetles. These can be found in many places around the Peruvian Jungle and Paititi. Venom can be used for Crafting Poison Grenades and Lure Arrows.
Extracted from BLISTER BEETLES. Used to craft deadly nerve gas for arrows and grenades.
Shadow of the Tomb Raider, Survival Guide