Treatise on the Nature of the Nyx

By Dr. Catherine E. Halsey
“	From the desk of Catherine Halsey:
The Nyx. A species whose very existence is one that is entirely a question. Not an answer. Life was so much easier when the only thing that was trying to kill us were a conglomerate association of bipedal lizards and birds with guns and laser swords. I have even looked into the Forerunner records that I have access to and nothing comes up about them. Nothing. The Forerunners were even unaware of their existence. They started a war with us in 2559. We had just barely survived the Covenant, the Flood, and the Forerunners. It was a war that nobody knew happened. One that could have gone very bad indeed. 
Origin
The origin of the Nyx species is one that is hotly debated in many scientific circles since their first attacks on Earth. No living specimens have been captured and when they die, their bodies immediately begin to decompose. This has made any understanding of them as difficult as it was against the Covenant in 2525. The consensus of their origin is that they are from deep space, from the void between galaxies, but I believe them to be a much older and more dangerous threat. Perhaps older than the Forerunners... 
Appearance 
The Nyx are affectionately referred to as insects by some of my colleagues, but I can assure you that this is not the case. They are more similar to a beating heart, with millions of veins and arteries reaching out from them. To assume that they remind one of a squid with jaws is probably not far from the actual answer. But they are not. 
Signed on this day, 12.20.2575,
Dr. Catherine E. Halsey	”