Daenerys is not just blood of the dragon. She is blood of the wyrm.
The History of Westeros Podcast, had a great episode on Septon Barth and the higher mysteries. Septon Barth is basically almost always right. When GRRM mentioned Septon Barth said this or suggested that… believe it. It is George telegraphing that what Barth was saying is extremely close to the truth.
In Septon Barth’s Dragons, Wyrms, and Wyverns, he speculated that the bloodmages of Valyria used wyvern stock to create dragons.
Where would this stock come from? Go back to the title of the book and remove the first comma and switch it to a colon. Dragons: Wyrms and Wyverns.
It is clear they used wyvern stock to make dragons, as wyverns are basically somewhat smaller dragons with beaks that do not breath fire. It is interesting to read some of the background in wyverns in literature and heraldry:
The Wyvern is a legendary winged creature with a dragon’s head (which may be said to breathe fire or possess a venomous bite) and wings; a reptilian body; two legs (sometimes none); and a barbed tail. A sea-dwelling variant, dubbed the sea-wyvern, has a fish tail in place of a barbed dragon’s tail. The wyvern in its various forms is important to heraldry, frequently appearing as a mascot of schools and athletic teams (chiefly in the United States and United Kingdom). It is a popular creature in European and British literature, video games, and modern fantasy. The wyvern is often (but not always) associated with cold weather and ice.
But what would make wyvern stock be able to breath fire? Fire wyrms. They are the only beast mentioned capable of breathing fire.
“Firewyrms. Some say they are akin to dragons, for wyrms breathe fire too. Instead of soaring through the sky, they bore through stone and soil. If the old tales can be believed, there were wyrms amongst the Fourteen Flames even before the dragons came. The young ones are no larger than that skinny arm of yours, but they can grow to monstrous size and have no love for men.”
Most terrible of all are the wyverns, those tyrants of the southern skies, with their great leathery wings, cruel beaks, and insatiable hunger. Close kin to dragons, wyverns cannot breathe fire, but they exceed their cousins in ferocity and are a match for them in all other respects save size. Brindled wyverns, with their distinctive jade-and-white scales, grow up to thirty feet long. Swamp wyverns have been known to attain even greater size, though they are sluggish by nature and seldom fly far from their lairs. Brownbellies, no larger than monkeys, are even more dangerous than their larger kin, for they hunt in packs of a hundred or more. But most dreaded of all is the shadow-wing, a nocturnal monster whose black scales and wings make him all but invisible … until he descends out of the darkness to tear apart his prey.
Viserion had shattered one chain and melted the others. He clung to the roof of the pit like some huge white bat, his claws dug deep into the burnt and crumbling bricks. Rhaegal, still chained, was gnawing on the carcass of a bull. The bones on the floor of the pit were deeper than the last time she had been down here, and the walls and floors were black and grey, more ash than brick. They would not hold much longer … but behind them was only earth and stone. Can dragons tunnel through rock, like the firewyrms of old Valyria? She hoped not.
Now lets compare the description above of Viscerion clinging to the roof like a huge white bat to this passage from Bran:
Bran ate with Summer and his pack, as a wolf. As a raven he flew with the murder, circling the hill at sunset, watching for foes, feeling the icy touch of the air. As Hodor he explored the caves. He found chambers full of bones, shafts that plunged deep into the earth, a place where the skeletons of gigantic bats hung upside down from the ceiling.
There really were dragons in Westeros. Not just the seadragon. And Bran is surrounded by their bones. Did someone say Wight Dragon?
I wonder if the seadragon is a wyvern as the description at the very beginning suggests. They are also associated with ice, and may be stock from which ice dragons are made. Seadragons can handle the cold of the deep in ways fire dragons would not. So seadragon wyverns may be the stock icedragons come from.
Though the bloodmages were alleged to have experimented mightily with their unnatural arts, this claim is considered far-fetched by most maesters, among them Maester Vanyon’s Against the Unnatural contains certain proofs of dragons having existed in Westeros even in the earliest of days, before Valyria rose to be a power.
The Targaryen “blood of the dragon” is literally blood of dragons.
Targaryens are the half-human half-animal hybrids George W. Bush warned us about in the State of The Union.
The tradition amongst the Targaryens had always been to marry kin to kin. Wedding brother to sister was thought to be ideal. Failing that, a girl might wed an uncle, a cousin, or a nephew; a boy, a cousin, aunt, or niece. This practice went back to Old Valyria, where it was common amongst many of the ancient families, particularly those who bred and rode dragons. “The blood of the dragon must remain pure,” the wisdom went. Some of the sorcerer princes also took more than one wife when it pleased them, though this was less common than incestuous marriage.
She, too, became pregnant, and like Alys before her, she gave birth to a stillborn abomination said to have been born eyeless and with small wings. She survived that monstrous labor, however, and was one of the two wives who survived the king.
Targaryens would not be the only human-animal hybrid in the series:
On the largest rock stands the keep of House Farwynd, named the Lonely Light for the beacon that blazes atop its roof day and night. Queer things are said of the Farwynds and the smallfolk they rule. Some say they lie with seals to bring forth half-human children, whilst others whisper that they are skinchangers who can take the forms of sea lions, walrus, even spotted whales, the wolves of the western seas.
Theron’s rather inchoate manuscript Strange Stone postulates that both fortress and seat might be the work of a queer, misshapen race of half men sired by creatures of the salt seas upon human women. These Deep Ones, as he names them, are the seed from which our legends of merlings have grown, he argues, whilst their terrible fathers are the truth behind the Drowned God of the ironborn.
The mazemakers left no written records, so we shall never know. Their bones tell us that they were massively built and larger than men, though not so large as giants. Some have suggested that mayhaps the mazemakers were born of interbreeding between human men and giant women. We do not known why they disappeared, though Lorathi legend suggests they were destroyed by an enemy from the sea: merlings in some versions of the tale, selkies and walrus-men in others.