Warning: Spoilers ahead for House of the Dragon’s season 2 finale and George R.R. Martin’s Fire & Blood book, on which the show is based!
Summary
House of the Dragonseason 2’s finale featured a few surprises, including a glimpse of a White Walker that fuels a theory connected to the Night King’s identity. This isn’t the first time the existence of the Night King and White Walkers have been referenced in theGame of Thronesprequel. Aside from King Viserys' mention ofAegon the Conqueror’s dreamand the threat of another Long Night,House of the Dragonseason 2 introduced Cregan Stark of Winterfell. While Jacaerys met with Cregan, the Warden of the North mentioned the threat of “death” beyond the Wall.
WhileHouse of the Dragonhas deviated from George R.R. Martin’sFire & Bloodbook, it’s unlikely an army of White Walkers and wights will appear in the show, at least among the direct conflict withinHouse of the Dragon’s current timeline. Those familiar withGame of Thronesand Aegon’s prophecy know how prevalent White Walkers are in House Targaryen’s fate. There’s so much of a link that many have linked Daemon Targaryen to the Night King.

10 Ways House Of The Dragon Season 2’s Finale Sets Up Season 3
House of the Dragon’s season 2 finale sets up several key events and battles for season 3. Here’s what’s next in the Dance of the Dragons.
Daemon Targaryen Is The Night King: Game Of Thrones Theory Explained
The Theory Has Existed From The Start Of House Of The Dragon
Well beforeHouse of the Dragonseason 2’s finale, popular theories emerged suggesting Daemon Targaryen is the Night King. The crux ofthe theories have implied that Daemon would eventually go on to become the Night King seen inGame of Thrones, which was set nearly 200 years afterHouse of the Dragon. Much of the evidence has stemmed from Daemon’s overall appearance compared toGame of Thrones' version of the Night King. Daemon’s clothing and style have also mirrored the Night King’s traditional look.
Daemon’s mysterious fate has additionally been used as evidence to support the Night King theory.

In general, much of the belief centered on theNight King being a Targaryenhas also come through the Night King’s ability to survive dragonfire inGame of Thronesseason 8. Since Daenerys could also be engulfed by flames and walk away unscathed, there was a thought it was common among all Targaryens. Only Daenerys had the power, as seen inGame of Thrones. Therefore, add that misinterpretation and Daemon’s look, and the theory ran wild.
Daemon’s mysterious fate has additionally been used as evidence to support the Night King theory.Daemon will eventually die during the Dance of the Dragons,it likely won’t happen inHouse of the Dragonseason 3. The book features Daemon and his dragon, Caraxes, fighting Aemond and Vhagar above Harrenhal, which becomes known as the Battle Above the Gods Eye. All four are killed in the battle, but Daemon’s remains are technically never found.

House Of The Dragon Adds Fuel To The Daemon Being The Night King Theory
Daemon’s Visions In The HOTD Season 2 Finale Help The Theory
No matter how ridiculous the Night King theory might be,House of the Dragonseason 2’s endingcertainly added fuel to the (dragon)fire with Daemon.“The Queen Who Ever Was” featured a scene in which Daemon had visions that were connected toGame of Thrones. Among the visions were the Three-Eyed Raven, Daenerys after her dragons were born, and a White Walker, seemingly depicting key moments in the future.
The White Walker seen inHouse of the Dragonseason 2 wasn’t the Night King, as the figure looked drastically different from the Night King inGame of Thrones. Still, the White Walker leading an army in Daemon’s vision still looked a bit like a Targaryen due to the facial structure and long white hair. Including the White Walker in Daemon’s vision was meant to warn of Aegon’s dream, but being an event for the future led some to believe the White Walker was Daemon’s destiny.

Daemon’s Vision Explained: Daenerys Targaryen, White Walker & More Game Of Thrones Connections
Daemon Targaryen has more visions at Harrenhal in House of the Dragon’s season 2 finale, connecting to his story, Rhaenyra, and even Game of Thrones.
Why Daemon Can’t Be The Night King
Game Of Thrones Already Shared The Night King’s Backstory
The Night King theory surrounding Daemon Targaryen certainly seems to be one that viewers either love or hate. That said, there’s no logical way Daemon could go on to be the Night King after the events ofHouse of the Dragon. For one, we directly saw the Night King’s origins after being transformed by theChildren of the ForestinGame of Thronesseason 6. Even ifHouse of the Dragonsomehow retconned the origins, the Night King was said to have been created thousands of years beforeHouse of the DragonandGame of Thrones.
The Night King theory is impossible, but that doesn’t take away the White Walkers' connection to House Targaryen and their future in Westeros

Sure, Daemon’s body is never found in the book, but could that really mean he somehow reanimates as the Night King seen inGame of Thrones? While I admit the Daemon theory is a fun one to ponder on the surface while watchingHouse of the Dragon. Still, it just wouldn’t make any sense, even with the show throwing in surprises to make it seem more plausible. The Night King theory is impossible, but that doesn’t take away the White Walkers' connection to House Targaryen and their future in Westeros, especially seen with the Night King’s defeat inGame of Thrones.