Game of Thrones' series finale, "The Iron Throne", saw Drogon fly away with Daenerys' body after Jon Snow killed her, but what happened to the dragon?
Drogon was last seen flying off with Daenerys Targaryen's dead body in the Game of Thrones series finale, so what happened to the dragon? Once seen as the hero of Game of Thrones, Daenerys became its final villain, descending into the "Mad Queen" after losing the people closest to her and discovering that her new love interest, Jon Snow, had a greater claim to the one thing she'd been working towards all along, the Iron Throne. She laid waste to King's Landing and all in it, with the help of her last-remaining dragon, Drogon.
Those actions led to a drastic reaction, with Jon Snow killing Daenerys in the Game of Thrones season 8 finale, "The Iron Throne". Daenerys' death prompted a furious response from Drogon, who turned his fiery gaze not upon the former King in the North, but Westeros' seat of power itself. Drogon melted the Iron Throne down, bringing the storied chair's history full circle, although the finale's script confirmed that this wasn't an intentional move by the dragon, but simply a result of his fury.
After burning down the Iron Throne, Drogon picks up Daenerys' lifeless body and departs, never to be seen again. It's last mentioned that he was flying East, but it's unclear exactly where he was going to, though it has led to plenty of speculation. In the book Fire Cannot Kill a Dragon: Game of Thrones and the Official Untold Story of the Epic Series by James Hibberd, Daenerys actress Emilia Clarke gives her own take on what happened to Drogon:
"People have asked me about that a lot. It's my tendency to be funny with it and say, 'Oh, Hawaii.' But honestly, if I'm really being very serious about the whole thing: I think he flies around with her body until it decomposes. I literally think he keeps flying until he can't fly anymore. He just keeps grieving."
While Clarke's comments aren't canon, they do indicate a suitably tragic end for Drogon. At the same time, though, he'd likely have to head somewhere - while there's no hard data, it's unlikely a dragon could fly for more than a couple of days at most without needing to stop. So even if he is simply waiting for Daenerys' body to decompose, he's probably headed to a known location in order to do so. The most likely of these, which has been speculated since the finale, is that Drogon went back to Valyria. This is where dragons originated, after all, and Drogon was flying around there in season 5, so it's somewhere he's familiar with. If the idea is that Drogon wants to be alone to grieve with Dany's body, it's the most plausible location.
The other possibility is that Drogon took Daenerys to Volantis, in the hope that she could be brought back to life. It's there the Red Priestess Kinvara is based, who wasn't seen again after her brief interactions with Daenerys, and it's possible this was the case. Although, while dragons are very intelligent creatures, it's not clear how Drogon would know a Red Priestess could bring Daenerys back to life. As the old home of the Targaryens and birthplace of dragons, Valyria makes more sense as a final resting place for Drogon and Daenerys in Game of Thrones - unless he really does just keep flying around until he dies.