Sunfyre

"Rhaenyra Targaryen was murdered by her brother, or rather, his dragon. It ate her while her son watched. What's left of her is buried in the crypts right down there."

- King Joffrey Baratheon tells Margaery Tyrell of Sunfyre devouring Rhaenyra Sunfyre​, known as Sunfyre the Golden​, was a dragon bred by the Targaryen dynasty. He was the personal steed of Aegon II Targaryen.

​​Aegon fed his half-sister Rhaenyra to Sunfyre while her son was forced to watch.

​In the books
​Sunfyre is featured prominently in the novella ​The Princess and the Queen. The event where he eats Rhaenyra serves as it's climax.

According to Archmaester Gyldayn, who gives a retrospective of the Dance of the Dragons, Sunfyre was the most magnificent dragon ever to fly the skies of Westeros. He had gleaming gold scales and pale pink wing membranes. In the sunlight his scales shone like beaten gold.

Sunfyre emerged from his egg on the Dragonmont. Aegon often rode him into battle during the Dance of the Dragons. Sunfyre was wounded at the battle of Rook's Rest, with one wing nearly torn from his body. Ser Criston Cole had cattle brought to him while he lay healing. The wing healed at an awkward angle and he would never fly the same. Lord Walys Mooton tried to slay the injured dragon, but Sunfyre burned his attackers.

Sunfyre killed another dragon, Grey Ghost, while returning to Dragonstone, either for Aegon or because it is the place of his birth. The fight left him with only one eye and wounds along his back, belly, and neck.

Sunfyre devoured yet another dragon, Moondancer, in the Fall of Dragonstone, but wounds he took from the fight left him flightless for the rest of his life. He remained in the yard of Dragonstone where he fell, where he was fed sheep by the garrison. Sunfyre ate Rhaenyra Targaryen at the bidding of Aegon II towards the end of the civil war. He eventually died from his wounds on the 9th day of the 12th moon, 130AL, Aegon wept upon Sunfyre's death.