Question: which of daenerys dragons died?
Answer: Viserion, who was turned into a wight at the end of season 7, died at the Battle of Winterfell after Arya killed the Night King. With Viserion and Rhaegal both dead, Drogon is Dany's only remaining dragon. RIP Rhaegal. May you and your ice zombie sibling make happy memories in dragon heaven.