Grim Touch (5e Equipment)
From D&D Wiki
Price per dose: 3,000 gp
Grim touch is a poison derived from the by-products of arcane experiments. It was first discovered by an unlucky wizard who didn't live long to celebrate his creation, but the apprentice that found his corpse also found the poison that killed him. Some unscrupulous wizards have been known to supply criminal organisations with the necessary components to create this poison, but most who use this poison create it themselves. The poison withers body and soul because of its magical nature, and some necromancers use this poison to set traps within their lairs.
A creature subjected to this poison must succeed on a DC 14 Constitution saving throw, taking 27 (5d10) poison damage on a failed save, or half as much damage on a successful one. A creature that fails its saving throw by 5 or more also takes 10 (3d6) necrotic damage.