"A twitching cathedral of ivory, flesh, and decay."
Nook is the name of a large creature that once hunted between the stars, in the High Wilderness. For unknown reasons, it came down to the Neath and embedded itself under the zee, where it currently slumbers. It seems to be similar to a long worm, entirely filled with teeth. It has been infested with parasites, similar to tapeworms. There are indeed people who live here, as this process makes the water breathable, moreso when mixed with wine. They have hollowed out a large number of the teeth to make caves and houses.
Nook changes the people who live in it, causing them to lose inhibitions and become more violent. The only source of light for the citizens are strange green polyps, which are (as one might imagine) fiercely fought over.