Battle.net

The Nydus Worm is an evolution of the Zerg Nydus Canal, a subterranean organic structure that interlinked areas covered by creep. Nydus Worms live inside a nest-like structure called the Nydus Network. A Nydus Worm can travel from the Network to any nearby location before emerging, in the process creating a tunnel beneath the battlefield. This huge creature is capable of stretching itself out to prodigious lengths to support the tunnel with its own skin and ribs. Zerg warriors can enter the tunnel via either the Worm’s head or the Nydus Network, and they can travel through the Worm at great speed due to a combination of peristaltic motion and chemical stimulants that direct their movements. Nydus Worms pose a grave threat to areas previously thought to be secure.