Meraxes was an apparently female dragon, ridden by Rhaenys Targaryen, the younger sister-wife of Aegon the Conqueror.
She had golden eyes and silver scales. Her skull is even larger than Vhagar's, and rumor has it that she was able to swallow a horse whole with ease.
Like Balerion and Vhagar, she was named by the rhapsods in a post-Conquest period after a god of the late Valyria.
Like Vhagar, Meraxes was born from an egg hatched in Peyredragon during the Blood Age, after the Scourge of Valyria.
During the Conquest, she was raised by the sister-wife of Aegon the Conqueror, Rhaenys. During the first movements of the Targaryens, Rosby surrenders without a fight when Meraxes and Rhaenys approach.
They then accompany Orys Baratheon in his campaign against the Storm King Argilac Durrandon. They begin by routing Lords Errol, Fell and Buckler.
From the air, they spy on the movements of the Orage troops, Rhaenys informing Orys of Argilac's numbers and movements.
They contribute to the victory at the battle of the Last Storm, which sees Orys triumph over Argilac. On Meraxes, Rhaenys is then welcomed in Accalmie to negotiate with Argella Durrandon.
Meraxes participates in the battle of the Field of Fire with Balerion and Vhagar. For the first time on a battlefield, the three dragons devastate the enemy armies and consume nearly four thousand men, including King Mern IX and his entire family, sounding the defeat and the end of the House of Gardener. Ten thousand men were severely burned and left with a lifelong stigma.
When the King of the North, Torrhen Stark, crosses the Neck, Aegon and his sister-wives ride north with their dragons and their entire army. The dragons impress the Nordians, who have heard the stories of previous battles.
If some propose to kill the dragons in their sleep before the battle, the king prefers to submit without fighting, rather than risk the lives of his men and the loss of his house.
Meraxes and Rhaenys are sent to Dorne, the only crown still escaping the Iron Throne. They pass through Le Voi, La Gracedieu, Bourg-Cabanes, and Lancehélion, all deserted.
Four years later, the first Dornish war broke out: Rhaenys and Meraxes set fire to Cabanesburg, whose inhabitants jumped into the water to escape the dragon fire.
They then take Boycitre, Bois-moucheté, Ordes-Eaux and finally, Lancehélion, where they find only old women and children. The Dornians rebelled as soon as the dragons left.
In the year 10, during an assault against Denfert, seat of the Uller house, Meraxes is killed by a scorpion arrow in the eye. In her fall she destroyed the highest tower and part of the castle walls. Queen Rhaenys is said to have died along with her dragoness.
In the year 13, the skull of Meraxes was returned to the Targaryens by the prince of Dorne Nymor Martell, the rest of his bones remain visible in the open air for decades under the walls of Denfert.