Aphoom-Zhah was spawned by Cthugha during his visit to Hyperborea. There, Aphoom-Zhah was worshipped as a god. This put him in direct competition with other polar gods (Rhan-Tegoth and Rlim Shaikorth) which began to dispute with him for devotees.
This situation remained stable for some time until the Elder Gods arrived to destroy them. Rhan-Tegoth was sunk in a comatose state and Rlim Shaikorth was thrown to the sea aboard an iceberg. However, when they were about to apprehend Aphoom-Zhah, it reacted with such violence that it froze the regions of Hyperborea Lomar and Zobna, giving rise to the North Pole.
This history is collected in the Pnakotic Manuscripts.
Aphoom-Zhah likely spawned the Gnoph-Keh, Rhan-Tegoth, and Voorm. Though no human cult worships this being, Aphoom-Zhah is revered by the Gnoph-keh, the Voormi and his own race of minions; the spectral Ylidheem.