"Aegon’s dragons were named for the gods of Old Valyria," she told her bloodriders one morning after a long night’s journey. "Visenya’s dragon was Vhagar, Rhaenys had Meraxes, and Aegon rode Balerion, the Black Dread. It was said that Vhagar’s breath was so hot that it could melt a knight’s armor and cook the man inside, that Meraxes swallowed horses whole, and Balerion … his fire was as black as his scales, his wings so vast that whole towns were swallowed up in their shadow when he passed overhead.”
The Dothraki looked at her hatchlings uneasily. The largest of her three was shiny black, his scales slashed with streaks of vivid scarlet to match his wings and horns. “Khaleesi,” Aggo murmured, “there sits Balerion, come again.”
"It may be as you say, blood of my blood," Dany replied gravely, "but he shall have a new name for this new life. I would name them all for those the gods have taken. The green one shall be Rhaegal, for my valiant brother who died on the green banks of the Trident. The cream-and-gold I call Viserion. Viserys was cruel and weak and frightened, yet he was my brother still. His dragon will do what he could not.”
"And the black beast?” asked Ser Jorah Mormont.
"The black," she said, "is Drogon.”