This tiny chunk of ivory resembles the fang of a snake.

When placed into an empty tooth socket, a snakeblood tooth adheres to your jawbone until removed. Placing or removing a tooth requires a standard action. A snakeblood tooth grants you a +5 alchemical bonus on saves against ingested poisons. This is a continuous effect and requires no activation.
In addition, a snakeblood tooth has 3 charges, which are renewed each day at dawn. Spending 1 or more charges enhances a tooth’s protective qualities as described below.
1 charge: You gain a +5 alchemical bonus on saves against all types of poison for 3 rounds.
2 charges: You and up to three allies within 10 feet of you gain a +5 alchemical bonus on saves against poison for 3 rounds.
3 charges: You gain immunity to poison for 1 round.

Prerequisites: Craft Wondrous Item, neutralize poison.
Cost to Create: 500 gp (plus 350 gp for base item), 40 XP, 1 day.