Yaksh is a gas-giant inhabited by a strange species of fungoid creatures known as Yakshians, of which little is known. Several cosmic entities have made their home there over the aeons.
For a brief period the Great Old One Hziulquoigmnzhah resided upon Yaksh after fleeing Yuggoth and the cannibalistic depredations of its parent Cxaxukluth. There it was worshiped by the Yakshians as a god, though it soon grew tired of these creatures and migrated to the planet Cykranosh.
Later the Great Old Ones Tsathoggua (who was also escaping Cxaxukluth's attentions) and Shathak met, mated and spawned the creature known as Zvilpogghua on Yaksh. However, Tsathoggua moved to Cykranosh on his journey to Earth, and Zvilpogghua left our solar system entirely, making its way to the planet Yrautram in the Perseus constellation. Whether Shathak remains in residence on Yaksh is unknown.