Design details:

This biomechanical dragon body is designed for speed and amphibious operation. He is fast in the air and glides easily when his gas bladders are filled.

Gills function as gills underwater. Outside of water, they are additional openings for gas venting and intake for management of the gas bladders, which fill with hydrogen that needs to be expelled if he's going to be diving.

The hind limbs and tail are very heavy and muscular for swimming; to compensate for this bottom heaviness in flight, there are additional gas bladders in the tail, and gills to vent them.

There are jets in the elbows, sides beneath the wings, tail paddle, and tail fins. These function for additional thrust in the air, or for additional speed underwater, like a jetfish.

The bright lines are luminescent in the dark.

The eyes likewise are adapted for underwater vision, with an additional eyelid as well as tapeta lucida.

There is a coating of blubber under the skin across much of the body. The skin is smooth and somewhat velvety. Due to the blubber, he is squishy and fun to poke.

Like Suns' dragon design, the artificial chromatophores on the skin are configurable and the colours and patterns can be changed for taste or camouflage. Sigs use this to display their serial number for differentiation to outsiders.