[Commissioned by @wannabedemonlord. The original was a chimera of whale skeletons and ammonites put together by a showman and marketed as the skeleton of a sea serpent. The commissioner requested that I make it an animal.]
Hydrarchos This colossal creature appears to
be somewhere between a snake and a whale. It has a single pair of broad,
powerful fins, and a long muscular tail. Its body is covered in a fine layer of
scales, and a low ridge grows along its back.
The
hydrarchos is one of the largest animals in the sea. Although the most massive
whales are heavier, none are as long as a hydrarchos, which can grow over 100
feet in length. They are an offshoot of the mosasaurs, and like them are
enormous carnivorous marine reptiles. A hydrarchos preys almost entirely on
whales and other enormous marine life, and even sea serpents may disappear down
its gullet. As the hydrarchos takes predominately large prey, it usually
ignores the comings and goings of humanoids in the water. They occasionally
mistake ships for whales, however, and woe betide the whaling crew that
launches harpoons at a hydrarchos on the surface.
As they
require enormous amounts of food to maintain themselves, most hydrarchos are
solitary except in the most productive waters. They are constrictors, wrapping
their coils around a whale and crushing it to death, or simply forcing its head
below water until the poor beast drowns. Mating is promiscuous and neither
parent plays any role in raising the offspring—the young are born live and swim
off immediately to find their own food. As a newborn hydrarchos is about the
size of a full-grown man, they are top predators from the start.
Hydrarchos as Animal Companions Starting Statistics: Size Medium; Speed swim
40 ft.; AC +1 natural armor; Attack bite (1d6), tail slap (1d4); Ability Scores Str 13, Dex 14, Con 12,
Int 2, Wis 12, Cha 6; Special Qualities
low-light vision, hold breath, scent.
7th-Level Advancement: Size Large; AC +3 natural armor; Attack
bite (1d8 plus grab), tail slap (1d6); Ability
Scores Str +8, Dex –2, Con +4; Special
Attacks constrict (1d8)
Hydrarchos are recorded along Gladia’s western coasts, though they are rarely seen. A vagrant specimen was recorded in the Swirling Sea just after the Kingdom of Kown-Dam’s fall; it severely disrupted shipping near Egdwen until a massive reprisal from the ruling Houses was able to destroy the beast. The skull was kept by House Isera, and eventually fell into the collection of the dock-lord that supplanted them.
Shores of Swords 