The following section contains information from a previous version of StarCraft II: Heart of the Swarm which is no longer valid.
The nydus destroyer is a zerg variant strain of the nydus worm that appears in Heart of the Swarm beta files. It could be summoned from a greater nydus network. It has an acid attack which it fires at structures only. It cannot load units.
The nydus destroyer's model bears a great similarity to the ash worm; it is possible one of the two models was adapted into the other.