Aww... It’s a cute baby dragon. It hatched with fins instead of legs and did not seem to react well to freshwater, so you relocated it to the nearest ocean.
Its dorsal fin has grown larger, and it rarely surfaces anymore. It must be close to maturing.

Young dragons are relatively defenseless. They are born with relatively soft scales, which are shed and replaced with harder ones as the hatchling matures. Once a hatchling’s wings grow in, it marks the beginning of maturation. At this point they are often capable of hunting on their own and are usually left alone by their mother.

A small, melancholy-inclined dragon, this creature skulks about the depths, waiting for human explorers or, much more commonly, other water dragons or sea serpents to approach her, asking for directions. She becomes unusually vigorous when asked for aid, and makes it her personal mission to guide everyone quickly and safely to their destination. She never asks for pay in return for her services, but those she assists are often so grateful that they shower her in gold and praise. Needless to say, she's got a lot of friends--and a lot of connections.