Nctosa and Nctolhu are twin Great Old Ones known as the Twin Spawn of Cthulhu, first appearing in Joseph S. Pulver’s Nightmare’s Disciple. They are the twin daughters born of Cthulhu and Kassogtha, and are said to be imprisoned, for now, within the Great Red Spot of Jupiter.
Both appear as colossal shelled beings with eight segmented limbs and six long, claw-tipped arms, vaguely resembling their half-sister Cthylla. The image of them sealed and waiting inside a planetary storm carries cosmic horror’s oldest dread intact: the power is not gone but sleeping, merely deferred.