Yuggoth

Yuggoth was the planet that served as the original home for the fungoid species popularly known as the Darklings. Following their war with the Tzun, the Darklings were driven to 61 Cygni. (PROSE: First Frontier)

Behind the scenes

 * Yuggoth in H. P. Lovecraft's fiction was an outer planet of the Sol system implied to be Pluto. It was used as an outpost for the Mi-go, multiple related species of light-averse creatures which were internally like fungi.