Seasmoke
A pale grey dragon who, unusually, accepted a second rider ÔÇö and made a bastard into a lord.
The beast itself
Seasmoke was a pale silver-grey, the colour of the haze that sits on the water off Driftmark on a still morning, and the name was not chosen idly ÔÇö at a distance over the sea he genuinely was difficult to pick out from the weather. He was middling in size all his life, never a great beast, but clean-lined and well-proportioned in a way the bigger dragons were not, and he was a strong flier over water, capable of long crossings without touching land.
His character was the interesting thing. Seasmoke was, for a dragon, sociable. He came when he was called, he liked being handled, and after his rider stopped coming he did not go feral the way an unridden dragon is supposed to: he stayed near the shore, kept to the same stretch of coast, and was seen for years circling Driftmark and the Spicetown road like an animal waiting for someone. Fishermen got used to him. That habit of tolerating people is the whole reason for the second half of his story, and it is not a habit dragons often have.
His first rider: Laenor Velaryon
Laenor claimed him as a boy on Driftmark and the two were well suited ÔÇö a light rider on a light dragon, both of them happiest out over the water and neither with much appetite for the courtly business waiting on shore. Laenor flew him in the Stepstones campaigns alongside Daemon and Caraxes, and by all accounts did it well; the Velaryon fleet below and Seasmoke above made a combination the pirate captains had no answer to.
It never became a partnership anyone made songs about, largely because Laenor's life was arranged for him by other people from the moment he was old enough to be useful. But those who saw him fly say it was the one part of his existence that was entirely his own, and that he stayed up longer than he needed to.
Claimed by: Addam of Hull
Seasmoke then flew riderless for years along the Driftmark shore, refusing to leave and refusing to be caught, and by the time the war came the dragonkeepers had written him off as a beast that had had its rider and would not take another. Then a shipwright's boy from Hull walked down to the water. Addam had no name worth the word, a mother nobody would discuss and hair of the wrong colour to be a coincidence, and he went up to a dragon that had turned away everyone else and was accepted in about the time it takes to tell.
The pairing suited both. Seasmoke was a dragon that liked people and Addam was a boy who had grown up among sailors and knew better than to be theatrical about anything. Within a year the shipwright's son was Addam Velaryon, heir to Driftmark, legitimised by an old man who had watched him do the impossible and drawn the obvious conclusion.
The blacks got a rider out of it whose loyalty ran cleaner than most of the trueborn ones, which was noticed and, being noticed, was resented. From outside the bond looked like the one straightforwardly good thing to come out of the whole war: a dragon that had been waiting on a beach for years, and a boy nobody had any use for, each of whom turned out to be exactly what the other needed.
What became of it ÔÇö if an ending is written, it is here. Spoilers.
Seasmoke fell at the Second Battle of Tumbleton with Addam on his back, fighting the men who had betrayed their own side. Addam died proving a loyalty nobody had been willing to grant him for free.
As for his first rider: Laenor Velaryon was cut down at Spicetown years before the war, in a quarrel the court was content to record as a lovers' argument gone wrong. Almost nobody believed that account then, and fewer believe it now.