The Kisser was a small stone knife carried by the Wraith, and was mottled almost the same color as its owner. The tip of the blade was laced with poison of such potency that it was capable of killing its target at a single stroke. However, its final victim proved to be the Wraith himself, who accidentally stabbed himself in the jaw with the blade after being startled, dying instantly. The Kisser was presumably lost with its owner, as it has not been mentioned in any subsequent books.
The Kisser appears in Outcast of Redwall.