An Inheritance of Stars
The Zerg are a race of mutated carnivorous insects from the planet Frezia. They are intelligent only through merit of a hive mind. The Zerg roam about the surface of Frezia hunting for bio-matter. They kill and recover any organic material they can find and bring it back to their hive spawning pools.
Zerg come in many different sizes shapes and types. They burrow, fly, climb, or crawl; the thew commonalities they all share are a chitinous hard shell, razor sharp claws, and a shared hive mind.
Some people have pointed out physiological similarities between the Zerg and the carnivorous spiders creatures of Inequity however there is no scientific basis of fact behind these rumors, the two are entirely separate species.