By the amazingly talented: https://www.furaffinity.net/user/hythegreykatt/ Hy will also be making up her own description and legend of this dragon as a canon guideline, mine may or may not be following the species make up she designs.

Physical description: Ammolite dragons appear abnormally slender in comparison to dragons with similarities to mollusks as the name would imply. Featuring skin instead of scales, with hardened points about the head similar to sea shells. Physically, ammolite dragons are most distinguished by their coloration and crystal frills, which protrude from the sides of their sleek flat rounded heads swept back like a blast. They smell like freshs fish and salt water. An ammolite dragon can grow up to a maximum size of 11 ft (3.3 meters) tall, 77 ft (23.4 m) long, with a tentaclespan of 80 ft (24.4 m). It can weigh up to 160,000 lbs (72.6 mt).

Combat: An ammolite dragon faced with a simple dual it believes it can win is generally a straight forward rush to otherwise pin the opponent and subsequently drown them in an extremely gummy slime they can extrude at will in prolific amounts not to mention the biting and clawing. Otherwise the dragon tends to overwhelm an opponent with stupid amounts of slime with guerrilla styled attacks popping in and out of range and avoiding harm to wither away at the opponents strength before directly assaulting again when it believes it can win.

Ecology: Their lairs tend to be anything from sunken treasure burdened ships to underwater sea caves, though the later is preferred if given the chance it has an air pocket for raising it's young. But due to it's physiology the dragon can be found at seemingly any depth that supports enough life to feed upon, short of carrion only diets like that of the lightless fathoms to which dead whales fall from their majesty to feed the hagfish and other strange things in the crushing black.

Parenting: They tend to lay their eggs among treasures of the deep, whether moved from a sunken ship to a sea cave or stolen away from non-sunken treasure laden ships, the dragon seems to want gold around before it lays it's clutch of about 30 eggs in total on a pile of gold and only gold as if it knows that metal doesn't corrode as much as silver and then wraps its whole body around it. It will stay put to protect its young for several years leaving only to feed however minimalistically as it can manage on the nearby sea life before immediately returning to it's hoard. Once hatched the dragon tends to supply food for the off spring and grow violent to sea life such as shark until all the wyrmlings fly the coop or nest as it were starting their own life before the female moves on just as well.