Arrow of slaying
An arrow of slaying is an arrow with unusual physical characteristics -- a shaft of some special material, feathers of some rare creature, a head of some strange design, a rune carved on the nock, etc. These characteristics indicate the arrow is effective against some creature type. If the arrow is employed against the kind of creature it has been enchanted to slay, the missile will kill it instantly if it hits the target creature.
Note: This item originally appeared in this form in the 2nd Edition Dungeon Master Guide for the Advanced Dungeons & Dragons game by TSR. Its inclusion here is for the purposes of providing context for the campaign only.