The popular theory circulating among fans of the television series and book adaptation of George R.R. Martin's "A Song of Ice and Fire" is that Daemon Targaryen, a prominent figure in the upcoming spin-off series "House of the Dragon," also doubles as the enigmatic Night King. This theory has given rise to numerous speculations and interpretations among the avid followers of the franchise.

"House of the Dragon," set to be released in 2022, will delve into the rich history of House Targaryen, a prominent noble family in the fictional world of Westeros. While little is known about the plot of the show, fans have been eagerly piecing together clues and historical information to anticipate what may unfold on their screens.

The theory posits that Daemon Targaryen, a legendary figure in Westerosi history, assumes the identity of the Night King. The Night King, in the original series, is an ancient entity and the leader of the White Walkers, a fearsome army of undead creatures. The Night King's ultimate goal is to wipe out humanity and bring about an eternal winter.

Supporters of the theory point to Daemon Targaryen's intriguing character traits, which exhibit a disregard for the rules and a desire for power. Daemon is known for his rebellious nature and his intimate relationship with his dragon, Caraxes. These characteristics parallel the Night King's relentless pursuit of power and control over the realm.

Furthermore, Daemon's physical appearance aligns with the Night King. In the books, Daemon is described as having a pale complexion, silver hair, and purple eyes - features synonymous with the Targaryen family. The Night King, too, possesses similar physical traits, with icy blue eyes and a pale, almost death-like appearance.

Another bolstering argument is derived from their respective storylines. Daemon's story arc is intertwined with his half-brother, Aegon II, in a violent civil war known as the "Dance of Dragons." It is believed that the Night King, also known as the Last Hero, was instrumental in ending the Long Night, a period of darkness and terror caused by the White Walkers.

These two narratives are linked thematically, as both involve a struggle for power and the preservation of humanity.

While this theory presents a compelling narrative, it is important to remember that it is purely speculative at this point. With limited information about "House of the Dragon," it is impossible to confirm or refute the hypothesis until the series airs in 2022. However, the speculation and anticipation surrounding the theory have undoubtedly added to the excitement and intrigue surrounding the upcoming spin-off.