From A Wiki of Ice and Fire
|Alias||Misery, the White Worm|
|Book(s)|| The Rogue Prince (Mentioned)|
The Princess and the Queen (Mentioned)
The World of Ice and Fire (Mentioned)
Mysaria was a dancer from Lys. She was taken as a lover by Daemon Targaryen in King's Landing, and quickly became his favorite. Around 105AC, Mysaria became pregnant with Daemon's child while living at Dragonstone. Daemon gave her a dragon egg for the child, which angered King Viserys. The king ordered Daemon to return the egg and send Mysaria back to Lys. The child was lost during her exile back to Lys.
At some point she returned to the Seven Kingdoms, and was in King's Landing to arrange for Blood & Cheese to assassinate Jaehaerys. Later she became Daemon's Mistress of Whisperers and was present in the Red Keep during Rhaenyra's brief reign there.