"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. “Klaleesi,” 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.
"And the black beast?" asked Ser Jorah Mormont.
"The black," she said, "is Drogon."