From A Wiki of Ice and Fire
Rhaego. © Morgainelefee
|Alias||The Stallion Who Mounts the World|
|Born||In 298AC, at Dothraki Sea|
|Died||In 298AC, at Lhazar|
|Book(s)|| A Game of Thrones (Mentioned)|
A Clash of Kings (Mentioned)
A Storm of Swords (Mentioned)
A Feast for Crows (Mentioned)
A Game of Thrones
After his father Drogo became sick from an infected wound, the sorceress Mirri Maz Duur saved Drogo's life by using blood magic. One of the effects of that magic was that Rhaego died right before birth. He was inhuman, hideously deformed and covered in dragon-like scales. He had the stub of a tail small leather wings, reminiscent of a bat. Rhaego was stillborn.
During her fever dream Dany sees her son tall and proud, with Drogo’s copper skin and her own silver-gold hair, violet eyes shaped like almonds. He smiles at her and begins to lift his hand towards her, but when he opens his mouth fire pours out. She sees his heart burning through his chest and in an instant he is gone, consumed like a moth by a candle, turned to ash. 
A Clash of Kings
In the House of the Undying Daenerys sees a tall lord with copper skin and silver-gold hair standing beneath the banner of a fiery stallion, a burning city behind him, which appears to be a vision of what might have been had Rhaego survived to be the Stallion Who Mounts the World.
A Dance with Dragons
While in Daznak's Pit after witnessing the slaughter Daenerys reflects that she once ate a stallion’s heart to give strength to her unborn son … but that did not save Rhaego when the maegi murdered him in her womb. She remembers the words of the Undying Ones:
|“||Three treasons shall you know. She was the first. Ser Jorah was the second, Brown Ben Plumm the third. Was she done with betrayals? ||”|
Shortly thereafter her dragon child Drogon appears in the skies above the pit.
Quotes about Rhaego
|“||Monstrous. Twisted. I drew him forth myself. He was scaled like a lizard, blind, with the stub of a tail and small leather wings like the wings of a bat. When I touched him, the flesh sloughed off the bone, and inside he was full of graveworms and the stink of corruption. He had been dead for years.||”|