Aura moderate necromancy CL 8th; Weight 1 lb.; Price 12,000 gp
Igilvar’s Fang (many imitations of the original have been made, but they are called “Igilvar’s Fang” in honor of the originator), is usually a thin, long-bladed, dagger, with a hilt of ebony banded with golden wire, and a wide guard. At the pommel is a white pearl. Igilvar was an infamous cleric of dark powers, who first made this blade for an unknown comrade who accompanied him on many quests in service to his bleak master.
It is a +2 dagger, which makes it useful in and of itself, but it has another power. When used to do precision damage, if it does at least 10 points, against any creature which has a poison attack (including poison breath or gaze weapons), it will magically replicate the poison and store this enchanted venom within itself. This changes the white pearl at the pommel to blood-red, indicating that the dagger is “charged”. It will hold this charge until the user drains the dagger (a free action). This is most often done just after a successful attack with the blade, but it can be done at any time to “empty” the weapon and prepare it to absorb a different kind of poison.
The poison stored in the dagger is exactly identical to the poison extracted, including Save DCs, effects, etc. The target is affected exactly as if it had been successfully poisoned by the original poison source.
The discharged poison vaporizes instantly on contact with air; to be effective, the blade must be plunged into something. Obviously, this is usually an enemy creature, but it could be a tankard of ale or a haunch of meat. At least half the blade’s length must be submerged for the poison to work. Poisoned food or drink will remain so for 1d4+1 rounds; after that, the poison will dissolve. As creature venoms rarely evolve to be used in assassinations, detecting such a poison in food is easy, a DC 10 Perception check. Making such a check means only a trivial amount of the poison was imbibed, granting a +4 on any saves.
Igilvar’s Fang can only charge itself when used in actual combat against a non-helpless enemy. The blade will not absorb poison from a container, a dead foe, or a willing target. How does it know? A wizard did it! (OK, a cleric, technically. Bite me, pedant.)
Some 10% of Igilvar’s Fangs will not match the description above, but they will always be daggers, and always contain some gem or decoration that changes color dramatically when the weapon is “charged”.
Craft Magic Arms and Armor, Poison. Cost 6,000 gp
The price is an approximation; I didn’t think the ability was quite worth kicking it up to the cost of a +3 weapon, but it’s better than a +2 weapon, so I split the difference.
There’s some great plot potential here. Igilvar’s Fang will hold a “charge” indefinitely. If there is some creature with unique venom around, usually paired, thematically, with a creature that can only be killed by said unique venom, then, the owner of the Fang might go on a hunt for the first creature. Alternatively, if the first creature is extinct, a rumor might exist of a rogue or assassin or the like who owned a Fang, or even the fang, and was entombed with it… and wouldn’t you know, in that rogue’s last battle, he fought the now-extinct creature and maybe, just maybe, got the venom from it before he croaked. Road trip! (With grave robbing. Actually, come to think of it, aren’t most D&D adventures basically road trips with grave robbing?)