Vial of PoisonNote: Currently(1.6) this Item is broken,and only harms the player.
Upon use it is thrown to create a poison cloud where it lands that will deal damage (20% of total health per second) to yourself and mobs. The cloud is stationary and could be used to deal damage overtime to mobs without being near them.It is a random drop from certain mobs and Chests. This cannot be crafted. [sic].
The Vial of Poison can also be mimicked by a potion called the Mysterious Potion which has a slight chance to be thrown like a Vial of Poison, thus being a gamble.