|Allegiance|| House Cargyll|
|Died||In 129 AC, at Dragonstone|
|Book(s)|| The World of Ice & Fire (mentioned)|
The Rogue Prince (mentioned)
The Princess and the Queen (mentioned)
A Game of Thrones (mentioned)
A Clash of Kings (mentioned)
A Feast for Crows (mentioned)
After the death of Viserys, Erryk joined Ser Steffon Darklyn and Ser Lorent Marbrand in siding with the blacks and joined the Queensguard of Rhaenyra, instead of supporting King Aegon II Targaryen.
Ser Criston, the Lord Commander of Aegon II's Kingsguard, tasked Arryk with infiltrating Dragonstone in the guise of his twin, Erryk. It is uncertain whether he was to kill Rhaenyra or her children. The twins came upon each other in one of the hallways of the castle's citadel and fought to the death, however. According to songs, the brothers professed their love and died in one another's arms after fighting for an hour. Mushroom, however, claims they called each other traitor and were both mortally wounded within moments.