Spear of Withering

Spear of Withering is a +4 weapon in terms of enchantment. It can inflict 1d6 +4 points of piercing damage and 4 points of poison damage. It has -4 THAC0 bonus, and a weight of 5 lbs. The speed factor is in fact 2, instead of 6 as stated in the in-game statistics of Baldur's Gate II: Shadows of Amn. This weapon also appears in Baldur's Gate II: Enhanced Edition. It can be bought from the weapons and armor merchant from the Ust Natha stores.

In-game description
"Spear of Withering +4 Carved from the heart of a rotten Treant, this spear smells of death. When held in your hands it groans a little as if reluctant to allow a living thing to touch it. In battle the Spear of Withering spits a foul poison into its target upon each succesful hit."