Apothecary Leech

Wondrous item, rare

This pulsing leech is specially bred and chemically treated by alchemists. Though it hungers for blood, it also hungers for poisons and diseases that contaminate blood. Applying an apothecary leech requires a DC 20 Medicine skill check. A failed check inflicts 1 damage and a check that fails by 5 or more inflicts 1d6 damage. If you are proficient with a healer’s kit, poisoner’s kit, or alchemist’s supplies you are proficient with this check. An apothecary leech can only be attached to a living creature.

When the leech is successfully applied your Hit Point maximum decreases by 1 as the leech continuously sups upon your blood. So long as the leech remains attached you have advantage on saving throws made against poison and disease. However, whenever you succeed on a saving through against poison or disease your Hit Point maximum decreases by 1 additional point as the leech’s growth is catalyzed by the contaminants it sips from your blood.

An apothecary leech can be removed with another DC 20 Medicine skill check carrying all the same risks as the check for applying it. Simply ripping the leech off requires a DC 15 Strength ability check, but each attempt inflicts 1d6 damage. After the leech has been removed it takes one week waste away to its original size, and which point it no longer reduces its user’s Hit Point maximum by more than 1.

If an apothecary leech remains attached to a creature that has died it burrows into the carcass and lays a clutch of eggs. 1d6 days later a swarm of feral apothecary leeches burst from the corpse. This feral leech swarm uses the same statistics as an insect swarm, but has a CR of 1 and any living creature damaged by the swarm has its Hit Point maximum reduced by an amount equal to the damage dealt.