Vermax

Vermax was the dragon of Prince Jacaerys Velaryon, the eldest son of Rhaenyra Targaryen and Laenor Velaryon, and he grew as fast as his rider rose. Green-scaled with orange flame, Vermax was a young but eager war-dragon, trained from the egg at Dragonstone and bonded to Jace since boyhood.

When the Greens contested the succession, it was Jacaerys who flew north on Vermax to treat with Lord Cregan Stark at Winterfell and Lady Jane Arryn in the Vale, binding the North and the Vale to his mother's cause with nothing but dragonfire and Targaryen pride. The alliances he won would matter as much as any battle.

Vermax's first and last battle was the Gullet, on the fifth day of the first moon of 130 AC, when the Triarchy's fleets fell on the Velaryon anchororage. Flying too low — struck by a crossbow bolt, or caught by a grapnel — Vermax crashed into a burning galley and went down beneath the waves. Jacaerys freed himself from the drowning dragon, but Myrish crossbow quarrels finished him in the water.