Gringolet

The Gringolet is a singular weapon. Forged out of a spirit by a liche, its powers enable it to slay ghosts and other undead creatures effectively (granting a bonus of 100% against undead). It appears in Ultima IX.

Description
The Avatar found the Gringolet in Cove, and used it in Covetous to slay Lothar, the skeletal representation of the sword's spirit, who was an obstruction in dungeon. The Avatar later sacrificed it so that the way to the liche would be opened.

Effectiveness of this Weapon

 * The damage of this weapon is 35(min) - 65(max), double against undead.

Trivia

 * Gringolet doesn't have to be sacrificed; there is an alternate way through Covetous to the lair of the liche, meaning that the Avatar can retain the weapon throughout the game.
 * Gringolet is the name of a horse from Arthurian legend.