Impaler

The Impaler is a spear +3 which deals an additional +10 piercing damage. It is probably the best spear in Baldur's Gate II: Shadows of Amn.

Baldur's Gate II: Shadows of Amn

 * City of Caverns - Prince Villynaty or King Ixilthetocal

In-game description
"The Impaler has a palpable aura of magic that hints at the vicious nature of the weapon and why it has been a favorite of several powerful orc chieftains in the the past. When a victim is struck they are, as one would guess, very nearly impaled, run through as the massive enchantment does its dirty work."