Moorkutlot (5e Creature)

Large beast, unaligned

Armor Class 13 (19 with temporary hit points active)
Hit Points 138 (12d10 + 72)
Speed 45 ft., climb 15 ft.

Saving Throws Str +9, Dex +8, Con +11, Wis +9
Skills Perception +9, Stealth +8, Survival +9
Condition Immunities blinded
Senses blindsight 90 ft. (blind beyond that radius), tremorsense 60 ft, 120 ft when moving or 10 ft when deafened, passive Perception 19
Languages —
Challenge 13 (10,000 XP)

Ambusher. In the first round of combat, the moorkutlot has advantage on attack rolls against any creature it surprised.

Echolocation The moorkutlot cannot use its blindsight while deafened.

Mookutlot Armor. At the start of each round, the moorkutlot has 35 temporary hit points. While the temporary hit points are active, the moorkutlot adds its proficiency bonus to its AC (included in the calculation) and it is resistant to bludgeoning, piercing, and slashing damage from nonmagical weapons. If the moorkutlot is exposed to a source of salt (such as seawater), the temporary hit points take acid damage which is doubled and the moorkutlot does not regain its temporary hit points until after a minute. Thunder damage and psychic damage ignores the temporary hit points.

Nocturnal Camouflage. The moorkutlot has advantage on Dexterity (Stealth) checks made at night.

Pounce. If the moorkutlot moves at least 20 feet straight toward a creature and then hits it with a bite or claw attack on the same turn, that target must succeed on a DC 18 Strength saving throw or be knocked prone. If the target is prone, the silent one can make one bite attack against it as a bonus action.

Superior Hearing. The moorkutlot has advantage on Wisdom (Perception) checks that rely on hearing and have disadvantage on saving throws against being deafened. If it fails a saving throw against being deafened, the condition lasts for double the typical time.

On the distant planet known by the inhabitants as Kaimere, the southern polar continent of Kaishel is a place of strange wonders, especially within its forests away from the coasts: colossal dinosaurs deftly moving through the forest and floating clouds and hives of magical organisms but all of these creatures share a common trait: they have been forced into a deft, eerie silence; birds do not sing, dinosaurs have ornate head gear, and even the Tlaton, native humans of Kaishel, use hand signs over spoken language. The sculptors of this context are the continent's apex predators, for which the Tlaton have many names: "Makers of Silence"; "Through Death They Make Quiet"; and "Kiss of Lead Blood" just to name a few. To the neighboring Kaimerens, the To Katen, these monsters have a spoken name: they are the Moorkutlot, "Architects of Silence, and to the rest of the Known World, they are known as the Silent Ones.
Relics of a Bygone Era. There is little fact and much superstition in regards to the origin of the Silent Ones of Kaishel. Some say they are ancient demons^[1], while others say they are homunculi^[2] created by the long extinct and tyrannical First Children, gone feral without their masters to tighten the leash. Some still say they are not even of this world, being creatures brought to Kaimere by the Portal from another planet all together. However, the truth, while to some disappointingly plain, is perhaps even more terrifying and beguiling: the Silent Ones and their ancestors are just as natural to Kaimere as the dinosaurs and humans that populate it.
Unsurprisingly, the ancestors of the Silent Ones are a group completely unique and far removed from any other tetrapod of Earth or Kaimere, being descended from a truly ancient lineage that traces their ancestry back to the very first harvest of life for Kaimere, lasting from the Late Devonian to the Early Carboniferous. The plants harvested from this time quickly spread across the planet, altering and stabilizing the atmosphere for the animals brought through the portal at the same time and leading to the time naturalists call the First Dynasty: "Dynasties" as Kaimeren naturalists define them are periods were the ecology of the world is stable enough that the Portal. During the First Dynasty, Kaimere quickly turned into a humid, hothouse jungle that drew aquatic animals, as happened on Earth, out of the water and onto land. However, where Earth saw an period of aridity that lead to the Permian, Kaimere remained a verdant global swamp much longer which resulted in clades that have no comparable analogues back on Earth.
Of this clade, the moorkutlot descend from a clade known as heterotherms, which trace their ancestors to the whatcheeridae^[3] a group of tetrapods so ancient they predate the split of amniotes^[4] and amphibeans. The name comes from their unusual metabolism, being able to jump between an inefficient but energetic endothermy to a sluggish torpor depending on food availability, a trait which helped them dominate the temperate regions of Kaimere closer to the poles, though most were small, arboreal generalists. Another trait ubiquitous in the clade is the secretion of non-Newtonian slime from the skin: this particular fluid hardens and strengthens proportionate to the force applied, a useful trait for an animal often at risk of falling from tall trees. Coastal regions are generally avoided by heterotherms as salt has the side effect of distilling and lessening the effects of the slime, as well as generally being uncomfortable and bad for their skin, though salt is unlikely to kill a heterotherm by itself.
Eventually, during the late Permian with the convergence of its tropical continents, Kaimere experienced a period of global aridity and the First Dynasty came crashing down. Any of those species that survived the initial climate change were swiftly driven to extinction by the synapsids^[5] and temnospondyls^[6] brought in by the Portal that were much more adapted to the arid climate, due to 40 million years of adapting to the Permian's arid landscape. However, a polar continent consisting of modern day Kaishel, Arvel, and Pakardia shared no terrestrial connections with the tropics and so was spared the invaders, allowing for the native fauna to adapt to the new landscape naturally. It was here that the heterotherms thrived.
Isolated from the Permian Dynasty, the southern heterotherms were the dominant predators, represented by forms that have changed very little from modern species such as the xhetsukaan of Pakardia. However, these forms seem to have disappeared during the early Cretaceous when a land bridge formed between one of the tropical continents and the polar continent, bringing competition from more recent harvests: dinosaurs. While it pushed their prey, another unique tetrapod group known as fabadonts, to extinction, heterotherms persisted as mesopredators in the shadows of the theropods, until about 40 million years ago when the closing of local gyres, separation of Arvel and Pakardia from the continent, and rising mountains drove several of the large dinosaurs to extinction. Many niches were taken up by multituberculates^[7] and small dinosaurs, but the apex predators came from the xenosimians, a clade of blind, arboreal heterotherms with astonishing hearing which in the evolutionary blink of an eye adapted into an entire order of arboreal and cursorial predators. The latter of these would give rise to Kaishel's most feared horror: Xenospiritus haemocementum, the moorkutlot, who remain the dominant predators to this day.
Architects of Silence. While the mookutlot's many names reference silence, naturalists note that they are somewhat misleading, as they are not especially quiet animals: as social animals and ones with eyes that are vestigial to the point of nonfuntionality, they make quite a bit of noise, with many types of grunts, snorts and hisses for communication and echolocation often compared to the crackling of fire. Rather, their names reference the silence that other animals in their environments are forced into, as they're presence and predation forces the native fauna into near complete quiet to avoid detection from predators that interact with the world through sound. Quite large and swift predators too, standing 5-6 feet at the shoulder and able to gallop at speeds of up to 45 mph. The second and third digits are hooved, further supported by a fleshy, nerve-laced pad that allows them to feel a meter down and further when in a sprint, while the first, fourth, and fifth digits remain tipped in hooked claws, although these are more for climbing than combat. Much like dolphins, the front of the moorkutlot's snout is filled up by a mass of waxy fluid known as a melon, which amplifies their echolocation. This organ is usually covered by their keratinized ears for protection, but these ears can open which with a strut on either side creates a massive radio disk. Normally they can hear hundreds of meters off but with the disk open they can hear even quiet footfalls from a mile away.
Like all heterotherms, moorkutlot also possess a coating of slime that protects them from most forms of harm, with many accounts from the Tlaton and Kaimerens of weapons simply glancing or bouncing off their skin. The Assembly's rare encounters with the silent ones shows that even low caliber bullets bounce off, though long rifles proved that slime does have its limits with regards to strength proportional to the force applied. However, as stated earlier, salt can easily distil this slime and as such the silent ones avoid coasts. Even coating weapons or armor in salt is can deter them. Their jaws are likened to those of sharks and for good reason: their teeth are sharp, serrated and constantly being replaced, and the jaws themselves strike a surprising mix of strength and flexibility, allowing for extremely efficient processing of whatever kill they make.
Most terrifying however is the venom they inject through their barbed tongue, which is attached to an extremely complex hyoid apparatus and wraps around the arms into a humped shoulder. In addition to being able to be fired out with enough force to break bones, the tip of the tongue forms a pocket filled with a substance that has the same properties as the spit of other heterotherms like the xhetsukaan, but much more potent in its concentration. As it moves through the body, each heartbeat causes the blood to briefly solidify, resulting in the locking of muscles and rupturing of blood vessels. Human sized victims can very easily die in a few agonizing seconds and a few cycles after the heart is solidified is all it takes to kill.
Despite these horrifyingly deadly traits, the trait that has lead to their continued dominance is their metabolism: ectotherms can produce in larger predator on less food which allows them to thrive in regions with low prey density, but endotherms tend to dominate due to their energy allowing them to be much more active predators. Heterotherms however have the best traits of both strategies and the moorkutlot takes this metabolism to an extreme within the clade: without food and sound guiding them towards prey, moorkutlot become extremely sluggish and will retreat to a sturdy tree or otherwise secluded area where they enter into a stasis until sound stimulates them to awaken. In this state, their bodies nearly shut down completely, to the point their hearts do not beat and they can go months without needing to breath, and through this stasis adults can live for centuries. It takes significant noise to awaken a moorkutlot from stasis, but their favored stimulus is the wilting cry of their fellow silent one after having made a kill, charging towards this dinner bell on fumes from their last meal and gorging themselves on whatever prey they spot along the way, including any fellow moorkutlot slain in the attempt. They can die in this state from overexertion, but even prey weighing several tons will die if injected with enough venom. Everything about them is specialized for efficiency.
It should come as no surprise given their bizarre and extreme mix of traits, the silent ones were a favored component of homunculi during the reign of the tyrannical First Children. Little is known of their invasion of Kaishel, but if the accounts of the Tlaton are to be believed, even though they captured their people, the First Children were actually beaten back and prevented from colonizing continent by the moorkutlot, so it is understandable that they found their traits admirable for soldiers in their armies, especially their nonnewtonian slime combined with the crystalline epidermis that makes class 3 homunculi so difficult to kill. To this day, the moorkutlot strikes fear in hearts of all humans of the Known World and beyond, and there is little that can stand up to the tyrant spirits of the silent forests.