Motomazor (5e Creature)

Gargantuan beast, unaligned

Armor Class 16 (natural armor)
Hit Points 315 (18d20 + 126)
Speed 0 ft., swim 80 ft.

Saving Throws Str +13, Con +13
Skills Perception +9, Stealth +14
Proficiency Bonus +6
Senses passive Perception 19
Languages —
Challenge 17 (18,000 XP)

Blood Frenzy. The motomazor has advantage on melee attack rolls on any creature that doesn't have all its hit points.

Hold Breath. The motomazor can hold its breath for 1 hour.

Siege Monster. The motomazor deals double damage to objects and structures.

Underwater Camouflage. The motomazor has advantage on Dexterity (Stealth) checks made while underwater.

Mosasaurs are one of the defining animals of Kaimere's oceans and seas, having ancestors that date back to the Cretaceous and receiving great success without the advent of the meteor to destroy them. While whales have taken up some of their niches, the dominant species of Kaimere's seas is the motomazor, eater of whales and sinker of ships. This massive predator has pushed the giant whales to the fringes and is part of the reason why the people's of Kaimere are restricted to the Known World.
Eater of Whales and Ships. Mosasaurs were diverse on during the Cretaceous period, with small fish and crustacean specialists swimming alongside 40-foot leviathans, but their rule was cut short by the meteor that struck at the end of the period. However, a similar event did not happen on nor did the meteor ever effect Kaimere, meaning the mosasaurs harvested prior had free reign to become truly diverse. During the Tyrant Dynasty, seven clades of mosasaur were found throughout the oceans, each armed with keen taste to find prey in the water, sight to capture it, and hemotoxic venom that caused prey to bleed out swiftly. While all these traits set mosasaurs up for dominion, it came crashing down due to the combination of rising aridity, volcanic activity, and shifting of continents that culminated in the Dynastic Extinction, of which four of the seven clades survived. In response, the Great Portal began harvesting from Earth and brought with it competition that supplanted the crocodile sharks that stepped up to the dominant predator niche: the Grandfather Whale Livyatan^[1], a massive, macroraptorial sperm whale, and the Grandmother Shark megalodon.
However, one of the clades of mosasaurs to survive the Dynastic Extinction was the intelligent, social whale lizards: these mosasaurs are recognized by their anatomy, which features a compact, stocky body with thick skin, very little fat despite the round shape, and a powerful tail that does almost all the propulsion, which allows them to maintain high speeds for long periods of time at the cost of maneuverability. Whale lizards only have one offspring at a time and maintain social bonds with their families even after spreading out to their own territories. In particular, a 35-foot long whale lizard from the northern border of the equator came to the Known World and posed fierce competition for the grandfather whale and grandmother shark. In particular, their habit of hunting down and killing the juveniles of competition was devastating and while they generally were solitary as adults, related animals would gang up on large threats like livyatan. This combined with a warming of the planet pushed the grandfather whale into a small population in the southern poler sea and the grandmother shark into a more subordinate role, and the maritime throne of Kaimere was once again held by a mosasaur. Thus began the rule that remains to this day: the rule of Motomazor.
With the giant cachalot gone, motomazor quickly grew from the massive 35-foot length to a colossal 50-feet and 50 tons and are the undisputed apex predator of equatorial oceans. Unlike their smaller cousins, motomazor normally doesn't hunt in groups but will corral prey towards each other in times of plenty and when food is scarce they will co-operate to bring down the largest whales. Motomazor generally prefers high fat marine mammals such as cetothere whales^[2] but will also take sharks, large fish, marine reptiles and even other mosasaurs without much fuss. The hunt usually consists of a few swift bites with their serrated teeth, retreating, and letting the venom thin the blood of their prey, returning once the prey has died of shock and blood loss, or is so close that the kill is swift. This is key to their 5 million year dominion, and there is no sign of their reign ending anytime soon. Due to their great size, adult motomazor only venture into the Inland Sea to hunt the juvenile megalodon that threaten their own offspring. Most curiously, motomazor seem to view ships as a threat and will attack them with violent retribution. This is one of the many reasons Kaimerans are restricted to the Known World and view the motomazor, rightfully so, as the embodiment of the danger their beautiful oceans pose. A threat ever lurking beneath the cerillian waves.