Nashor's Tooth

Supposedly once a powerful dragon, Nashor is now nothing more than a legend. This dagger, which Thovinion found while travelling to The Kingdoms from his hometown outside of civilization's borders, is a level 4 Tooth of Chaos dagger (page 204 in the PHB2). It can change shape, though frequently it appears to have a wavy blade with a variety of colours swirling about just beneath the surface.