Mother Darkness is a potent neurotoxin, derived from bark scorpion venom. It causes muscular paralysis, a spreading numbness, and hallucinations, causing -3 to both Agility and Perception, as well as doing 80 damage over the course of 10 seconds. This makes it very useful against faster enemies and enemies who rely on marksmanship.
It is less lethal than bleak venom in terms of raw damage, but remains a very useful poison for a wide variety of situations. Unfortunately, it is much harder to create than bleak venom or Silver Sting. Like all venoms, it can be applied to any unarmed or melee weapon (including thrown weapons) to allow you to envenom a target on a successful hit. Note that one dose of poison lasts until one successful strike or thrown projectile only (oddly, a stack of throwing weapons remain poisoned until one of them actually hits).
Mother Darkness (3)