Voracious Craw

Voracious Craw were worm like creatures.

An adult Voracious Craw somewhat resembled a gigantic tapeworm or other mollusc, large enough to be seen from space when cruisisng just above a planet's surface. As the name implied, the Craws where permanently hungry, and would eat everything that they could, animal, mineral or vegetable. I was unknown how a Craw actually ate. Anything below the mouth of a Craw was pulped and sucked up into the mouth itself, but as the Craw did not actually touch the food. Although the Craws where a species without technology, the presence of a Craw nearby could send most technology haywire, and the Craw where somehow able to cross vast distances of space without suffering any ill effects.

When a Craw arrived at a planet, the first thing that it did was check to see if another Craw had got there first. If one had not, the Craw then proceeded to devour everything on the planet that it physically can. If it meets another Craw, the larger one is allowed to feed on the planet and the smaller must leave. The sound of a larger Voracious Craw can be modelled by playing back and distorting human burps, and this technique was used to great effect to save the inhabitants of Tiermann's World. (NSA: Sick Building)

Error
The cover of Sick Building shows the Craw with teeth but this is not so.