Whale-eaters

A species of large beasts living in the Janta Strait and the Spired Sea which feed on stone-crawlers on the ocean floor, and gradually go mad from the gimyndine in the crawlers before surfacing to hunt crest-whales. The creatures resemble a kind of gargantuan mer-wolf, and are harvested for their large hauls of high-quality gimyndine and other useful materials, forming the backbone of the Yejian economy and power system.

Naturally, the creatures vary in size and behavior, with the largest being capable of threatening cities. But as the size rises, so too does the haul, and thus many Yejian firekeepers have made a career around hunting the creatures and innovating novel techniques such as the rolling couple to help conquer water and, by extension, the creatures.