Scorpion Stinger (3.5e Equipment)
From D&D Wiki
Scorpion Stinger: This +1 poisonous speed dagger has a handle worked in the likeness of a scorpion, its tail ending at the blade. Those injured by the blade can become poisoned. They temporarily receive 1d3 points of Constitution damage and an additional 1d3 points of Constitution damage one minute later. Each instance of damage can be negated by a DC 12 Fortitude save. Also, the scorpion stinger’s wielder is immune to poison effects resulting from injury. It does not grant protection from spells and supernatural abilities that poison.
Faint necromancy and abjuration;CL 5; Craft Magic Arms and Armor, poison, neutralize poison; Market Price: 25,652gp