Lychanid

 An ancient species of self engineered fungal hive mind organisms, they were known to exist by the Queldari since at least the year two billion BCE.  Once a humanoid species, long ago they had engineered themselves into massive living minds beneath the surface of planets, capable of growing any technology needed.  They are also capable of growing free roaming Lychanid organisms to perform various tasks.  The Lychanids keep a low profile and only intervene in wider events if necessary, however they have provided key support to other organic life when it seemed the Silicates or rogue Artilects might prevail.

The Lychanids may once have been Queldari, or possibly some other humaniod or even on humanoid organic life.  

It is discovered that the Lychanid presence in the galactic super cluster is far greater than previously imagined, with fungal scout clusters discovered on the vast majority of inhabited worlds.  Each cluster operates semi independently but maintains contact with the collective using Fractal Data Spores which can travel at relativistic speeds and carry vast amounts of information encoded in their DNA.  This allows the collective, which at the time of humanities emergence was over two billion years old, to communicate at a relatively fast pace on galactic timelines and maintain a shared sense of purpose and strategy.

The Lychanids have a Green Ichor that was synthesized from the Grey Ichor in ancient times, possibly before even the Blue Ichor was created by the Queldari.  Green Ichor is Delta type meaning it has a high level AI living in it's hive mind, however it is under direct control of the Lychanids and is one of their main tools to protect themselves from other powerful species that would seek to encroach on their territory.