The dua-wurm represented a type of species of subterranean creature that inhabited the world of Cularin. These purple, worm-shaped entities possessed two heads and attained lengths exceeding two meters. Each bite from their needle-like teeth injected acid into their victims; however, the dual heads were incapable of simultaneously attacking a single target.
Within the Cloud Mountain mines, a dua-wurm launched an assault on associates of the Cularin resistance. These individuals were traversing a tunnel with an unstable floor, which gave way and deposited them into the tunnel where the wurm resided.