Serina: Imperious River Dragon

With the end of the ice age, the warm climate has had a massive cascading effect on all life on Serina. With the constant precipitation and waterways that riddle the continents, plant life flourishes like never before. With the plant life flourishing, the herbivores that feed upon it grow to immense proportions and numbers. With herbivores in great size and population, the predators too have grown to match them. No prey is larger and more numerous now than the skuorcs, the gantuans and skulossi which tower to dimensions greater than anything that has roamed Serina in previous eras. And so predators have reached scales like none seen before in order to hunt them.

In the swollen waterways of Serinarcta, there is an inland predator more massive than any other, built to dispatch such immense titans in one bite. Longer than a bus and nearly twice as heavy as an elephant, this is the undisputed ruler of the wetlands. Jaws up to six feet long contain huge spike-like teeth and a bone-crushing bite, their primary weapon of choice against its preferred prey, the vast multitudes of animals coming down to the shore to drink. A varied diet of such beasts as large trunkos, thorngrazers, skuorcs, giraffowls, and cutthroats, or anything else that moves. Like a crocodile just below the surface, it waits for the regular arrival of the endless herds, easily hidden by just a few inches of murky water above it, despite its gigantic size, and with one lightning strike it snaps up an unfortunate victim. Once clamped tight around its quarry, nothing escapes its jaws. Prey up to to three-hundred kilograms in weight can be swallowed whole after capture, and writhing and coiling its sinuous body allows it to easily tear apart larger animals, especially when working in tandem with other feeding river dragons.

Although they can reach gargantuan proportions, few actually reach such sizes due to the structure of their social hierarchy and physiology. River dragons live in territorial clans which stake out large swathes of habitable land, defending it viciously and persistently from neighbouring clans. Within these clans there is a dominant breeding pair which actively suppresses the growth of the other clan members through ritualistic biting and aggression, preventing them from ever reaching full size until either the alpha pair dies or the smaller individual leaves for its own territory. This bullying extends down the ranks of a clan, and individuals at the bottom of the pecking order may be only twenty feet in length. This helps keep the river dragons from competing with one another, as the smaller dragons will be limited to smaller prey and their greater underwater agility allows them to capture swimming prey that the larger adults, which specialize in large terrestrial prey, rarely bother with.

The river dragon is semi-aquatic, but not particularly swift on either land or underwater as adults due to their massive size. It travels over land infrequently due to being very slow and vulnerable to attack from terrestrial predators like cutthroats. When threatened, it will defend itself from the front with vicious bites, while striking with swipes using its powerful tail from the back; being whacked by a tail able to launch a ten-ton carnivore off the ground can easily cause catastrophic injury. They are comparatively better swimmers, but they prefer shallower water due to being predominantly air-breathers, as they can simply rest at the bottom and lift their head periodically as necessary to replenish their oxygen, and have an inefficient body shape for sustained underwater locomotion. It does often haul out along the shore to bask and allow small birds to pick parasites from out of its skin, however, sometimes several at once.

This preference for shallower water limits their presence from large bodies of water like the Polar Basin and the Centralian Sea to occasional vagrants, which is perfectly fine when they prefer to prey on land animals, although they are also occasionally known to forage along the coast in brackish waters. Murkier waters are also preferred, as it is much easier for them to ambush drinking animals. Juveniles are more wide-ranging, as they tend to disperse far and wide to establish their own territories or join the clans of foreign adults and have a diet heavier in aquatic prey like fish and snarks. Only the very largest and healthiest mega-skuorcs may be spared from the jaws of the imperious river dragon, as the gigantic eelsnake is will attempt to topple such huge prey by coiling its body over them to drag them down into the water with its body weight, often helped by others of its clan attacking together at once. The fear of a watery grave is one that dwells within the minds of every thirsty Serinarctan animal.