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From Pathfinder #157: Devil at the Dreaming Palace, which isn't enabled.

Reaper's Lancet

ITEM 5
Price 200 gp
Usage held in 1 hand
Bulk 1
Category martial
Group sword
Damage 1d6 piercing

Hendrid Pratchett himself designed this custom skull-topped +1 striking exquisite sword cane and had it gilded in high-quality gold. Its first victim was the very smith whom Pratchett commissioned to craft the weapon, so the means of its construction are a secret known only to Pratchett. The magic of the Reaper's Lancet applies to both the blade and the sheath, making them each effectively a +1 striking weapon, but only if both are wielded by the same creature-if the two components are shared between creatures, only the blade retains the rune's magic.

Reaper's Lancet has a hidden reservoir inside the skull that automatically applies a new dose of poison to the blade after the previous dose was expended with a successful Strike. The reservoir must be filled manually (a process requiring 1 minute) and is large enough to hold only 3 doses at a time. Any sort of injury-delivered poison can be placed in it, though all doses must be of the same poison. The Price of the poison is not reflected in this weapon's listed Price.

Activate Interact
Trigger You damage a creature with Reaper's Lancet

Effect You poison the creature you hit with the poison currently in the reservoir.
Pathfinder #157: Devil at the Dreaming PalaceOGL