The Hydra, dragons from beneath the waves. What little is known of them is gleamed from those outcasts or adventurers who deign to rise from the depths and live on land.
The children of the twin-headed Primordial, Frost and Flake, the Hydra are presumed to be the first of the dragonfolk. It is claimed that they were created by the dragongod of the seas shortly after the first clash with the Umbra. Sculpted to act as custodians in their absence and against further incursions should the Godshield fail.

Appearance wise Hydra can vary, being any color you'd expect of a fish, though usually very colorful like a beta fish. They are covered in scales and gills. In rare cases, they can grow fin-like wings capable of short glides. Growing at a rate similar to other dragons, they, they typically grow up to 6-9ft by the time they reach maturity. However, though slowed, they will continue to slowly grow for the rest of their life.

No surface dweller has seen a Hydra die of old age. At some point, several hundred years into their life, they hear "The call of the sea," a notion to return home beneath the waves. Once the call is answered, these Hydra are never heard of again above the waves. The oldest anyone knows of made it to 500 years before they returned to the sea.

Of their own culture, little and less is known. Those who make landfall are reluctant to shed light on their watery homes. At most, the people of land are tenuously aware of the existence of underwater kingdoms and the apparently fierce rivalries which drive most Landbound Hydra upwards. Those who make the surface their home tend to be loners, but there are those who congregate and conform to Kabaiyo culture. They take well to the more feudal styles of community to be found in Kabaiyo kingdoms. Whispered in private moments, they have been heard murmuring prayers and mantras of teachings and a religion only they know.
Hydra are typically mysterious, stoic, and guarded. But, they can be befriended with time and patience. There's a popular saying, "The fishfolk are fierce friends, and fiercer enemies."

The last thing you want to see is a Hydra coming at you in anger. And the first thing you want is a Hydra at your back, calling you ally, or even as family. Though loners, once they find someone or some group they like, Hydra can latch on like an affectionate cat. Aware of threats you don't even know exist, (or might not exist), and always trying to keep you safe from said threat.

For their naming conventions, their native tongue is just odd guttural noises to surfacedwellers. So typically, they're given nicknames, which range from simple and jokey to serious titles or in rare cases, terms of endearment. such as; Spike, Fin, Destroyer of Thousands, Big Blue n' Red.

Drawn for me as part of my worldbuilding by  Nyne !