Jes is a rare breed of aquatic dragon, suitable for deep water hunting as well as shallow, she's VERY fast through water and generally eats large water creatures or groups of smaller ones.
Hunted to near extinction, there are about 50 of her breed in the world where once they could be found in various colours in most large bodies of water world wide.
Jes herself is one of a set of triplets of which 2 survive (the other survivor being my friend's character) and lives in a large mountain lake that's connected to the sea via a river at it's southern most point. She's known to the locals as a protector, fending of larger dragons within her territorial area, which covers most of the huge lake. The villages around the lake in turn protect her from the multitude of hunters and poachers, the only people she will in fact eat.

Her crests and angler thing can glow but can be made to stop, allowing stealthy hunting as well as luring unsuspecting creatures with GLOWEY

-The little man is for size reference but she's friendly enough to generally not eat people.