Ycnàgnnisssz is a Hyperborean name for one of the progenitors of the gods (Azathoth being the other) according to the genealogy in The Parchments of Pnom and the related Book of Eibon. All that is known of it is that it is from the dark star Zoth, and it spawned Zstylzhemgni. It is a fissionary being and is probably either Abhoth or Ubbo-Sathla. However these two names are also Hyperborean, so it may be a different entity. Possibly it is the Nameless Mist or The Darkness, or possibly it is the Azathoth-Ubbo-Sathla, the bivalvular shape of Azathoth.
Behind the Mythos Edit
The character first appeared in Smith's 1934 "Genealogical Chart of the Elder Gods" answer to Barlow's now missing style sheet. (Selected Letters of Clark Ashton Smith 189)
Azathoth Ycnagnnisssz (reproduced by fission) (fissionary being from | the dark star Zoth) | \ Cxaxukluth \ (androgyne) \ / | \ \ / | \ \ Tulu | Ghizguth-----------+-----------Zstulzhemgni | (male) / (female) | / | / Hzioulquoigmnzhah Tsathoggua--------+--------Shathak (male) | | Zvilpogghua | | Sfatlicllp (daughter who mated with Voormi) | | Knygathin Zhaum (peopled Commoriom by fission after the human residents had left)