A shamkniv is an ogre torture device used to torture Mercadirs who fail their assignments. Keefe is threatened with this in Nightfall, and it's used harshly on Lady Gisela in Neverseen. King Dimitar wields this weapon. It's jagged so each cut leaves a scar, and if someone seriously disappoints the king he dips it in flesh-eating bacteria. Usually it's only used for one or two cuts for a first offense, but in Lady Gisela's case an unknown elf sentenced her to many. Lady Gisela was cut in places such as her neck, face, and chin. In book 6, Nightfall, it is revealed by Sophie Foster that Alvar Vacker was hurt in several places by a shamkniv.
A dagger-size weapon, short and heavy, made of black metal that curves like a crescent moon.