Lurks are a family of creatures which emerged from the same group of Iythiods which produced the Hexaclawer and these creatures evolved in tandem. Living in low oxygen rivers and swamps, both lines developed the ability to breathe air, both used their lobed fins as anchors against river currents and as swamps and waterways would on occasion dry out both developed the ability to crawl about on land. The primary difference between the two lines was size and diet: the ancestors of hexacrawlers were small bottom feeding herbivores while the primordial lurks were large predators that ate said bottom feeders. Predation and Food were two major things which drove the evolution of Hexacrawlers, with a fast life cycle allowing them to adapt to life on land more quickly. This allowed their populations to spike and fed predator populations. The Lurks were slower to change, being larger, less numerous and slower breeding. Even so they soon found a niche. Hexacrawlers still had to return to the water to moisten their skin, give birth to fry and to cross bodies of water in their search for plants to eat and when they did so, they were vulnerable to ambush. The topmost eye of lurks evolved an elevated mound allowing them to peer out out from beneath the surface in search of prey while giving little clue of their presence. But while most of their kills were made in the water, Lurks such as this Swamplurk were more than capable of beaching themselves and pulling hexacrawlers under.This swamplurk is fairly typical of the original lurk lineage: a long body that's flat in the front and narrows out towards the end with six lobed fins with small claws to pull it along and a triangular head with a set of powerful jaws serrated triangular slicing teeth. It is about 3 meters long and weighs 150 kilograms. There have been a variety of variations on this theme, some getting as long as seven meters while weighing up to a tonne. Numerous variations of this theme have arisen among numerous lakes, ponds and estuaries before and after the great impact (though some would evolve out from it to fill other more terrestial niches). Swamplurks have a low metabolism and can get by with one meal every few months.