A molleung worm functioned as a cofferdam in both space and underwater environments, and it was a bio-engineered creation of the Yuuzhan Vong. This worm was utilized within the atmosphere to deploy cargo from a transport ship down to a complex situated on the planet's surface. When submerged, the worm served to connect underwater compartments. Frequently, it is deployed to assault enemy forces preceding the arrival of the transport vessel. Furthermore, it is capable of providing support to troops during combat operations.