Vermithor

Legend says Vermithor hatched from an egg the princess Rhaena left in the cradle of her newborn brother, Prince Jaehaerys, in 34 AC. The dragon grew alongside the boy and in time became his mount.

When King Aenys I died, Vermithor's fire joined Quicksilver's and Silverwing's to light his funeral pyre. The royal family fled afterward to Maidenpool, and having Vermithor at his side counted for Jaehaerys when the lords of the realm had to choose between the young prince and his uncle, King Maegor: by 48 AC the boy was already flying a grown dragon.

After Maegor's death, Jaehaerys flew with his sisters Alysanne and Rhaena to King's Landing to claim the throne, arriving at the Golden Wedding held at the Dragonpit on Vermithor's back. Soon after, the young king and Alysanne fled with their dragons to Dragonstone to marry in secret, and stayed there through the rest of the regency.

When Jaehaerys came of age in 50 AC, he returned to the capital on Vermithor. He had the dragon circle the city three times before landing at the Red Keep, so all of King's Landing could watch him arrive.

King Jaehaerys spent much of his reign travelling the realm and holding audiences with his vassal lords, almost always on Vermithor and with Alysanne alongside him on Silverwing. In 52 AC he visited the Vale of Arryn and flew to the top of the Giant's Lance and the Eyrie. The following year he toured the Riverlands; he was at Stone Septry when word reached him that Alysanne was giving birth to Princess Daenerys, and he flew straight back to the capital.

In 54 AC the king and queen travelled to Oldtown for the High Septon's funeral. Vermithor landed before the Starry Sept while Silverwing settled on the Hightower, and from there the king also flew out to the Arbor. That same year, when Rhaena returned to the capital on Dreamfyre searching for her daughter Aerea, Vermithor and Silverwing took to the air roaring, and for a moment it was feared the dragons might fight each other. Jaehaerys even considered chasing Elissa Farman's ship into the Sunset Sea on Vermithor, but the queen and the small council talked him out of it.

With the Dragonpit finished that same year, Balerion and three lesser dragons were housed there, but Vermithor and Silverwing kept sleeping at the Red Keep, close to their riders. Jaehaerys flew Vermithor over the Red Mountains during the Third Dornish War and burned the Vulture King's camps; years later he and his sons burned Prince Morion Martell's fleet from dragonback during the Fourth Dornish War. The king's last known flight came in 89 AC, a royal progress through the Westerlands and the Reach.

Jaehaerys died in 103 AC, and Vermithor let no one else ride him again. The dragon hid away in a cave on Dragonmont, where he would remain riderless for decades.

By the time the Dance of the Dragons broke out, he was, after Vhagar, the oldest and largest dragon left in Westeros. His size made him less agile in the air than younger dragons, but his fire at its height could melt steel and stone.

When the Dance of the Dragons broke out, Prince Jacaerys Velaryon sought riders for the wild dragons sleeping at Dragonstone. Lord Gormon Massey tried his luck with Vermithor and burned to death before he even got close. The dragon eventually yielded to a baseborn smith, Hugh Hammer, who rode him for the rest of the war.

Vermithor tolerated men better than most of the wild dragons at Dragonstone, unusual for a beast that had gone without a rider for decades. Even so, he remained an old, heavy animal, far slower in the air than younger dragons, though his size and fire more than made up for the lack of agility.

Vermithor fought in the Battle of the Gullet alongside Silverwing, Sheepstealer, Vermax and Seasmoke, when the five dragons fell upon the ninety warships the Triarchy had sent to Westeros's shores.

Later, during the fall of King's Landing to the Blacks, Vermithor and Silverwing landed together on Rhaenys's Hill, facing the Dragonpit.

Vermithor and Silverwing fought in the Battle of Tumbleton alongside Ulf the White, though both riders ended up betraying Queen Rhaenyra to join her enemies. Together with Tessarion, Prince Daeron Targaryen's dragon, they set the town ablaze in a sea of fire.

When the second battle of Tumbleton broke out, Vermithor and Silverwing were south of the town and their riders could not reach them. Two-score knights surrounded Vermithor and wounded him a dozen times before he took to the air; enraged, he attacked men on both sides and burned Lord Stanton Piper and Lord Lyonel Deddings along with their men.

Ser Addam Velaryon sent his dragon Seasmoke against Vermithor to stop him, and the two beasts rolled tangled through the mud until Vermithor, bigger and stronger, tore off Seasmoke's head. But his wings hung in tatters and he could not take flight again; he died soon after. Years later, Lady Sharis Footly had the heads of Vermithor and Seasmoke cleaned and put on display in Tumbleton's square, charging any who wished to see or touch them.