"Game of Thrones" Season 7 Episode 7 finally revealed what the fans have been speculating for years, even decades if we consider the "A Song of Ice And Fire" novels -- Jon Snow is indeed the son of Rhaegar Targaryen and Lyanna Stark. The show took it one step further by stating that he is actually heir to the Iron Throne since his parents had been secretly married under the Light of the Seven. And with Jon being the secret Targaryen, we can't help but wonder if he is the only one.

The three heads of the dragon prophecy

In one of her House of the Undying visions from "A Clash of Kings," Daenerys saw her late brother Rhaegar.

He was talking to his wife Elia Martell about their newborn son Aegon and his role as The Prince That Was Promised who has the song of ice and fire. Then, Rhaegar went on by saying how there must be one more since the dragon has three heads. This, of course, refers to Rhaegar's desire to have one more child. And since Elia couldn't have any more children, he eventually found Lyanna and fathered Jon.

But what if Rhaegar was wrong? What if the prophecy doesn't refer to his children? After all, his other two children are dead, their skulls crushed by the Mountain in the Sacking of King's Landing. That leaves only Jon as one head of the dragon. But who are the other two? While the first one is pretty obvious as Daenerys is already the Mother of Dragons, we'll have to do some digging to find the other one.

There's another secret Targaryen

Since the prophecy is clearly referring to three people with Targaryen blood, we must find another secret Targaryen. And the Reddit user Saravian speculates that this person is none other than Tyrion Lannister who is, in fact, the son of the Mad King Aerys and Tywin's wife, Joanna Lannister. Now, let's explain how is this possible:

  • According to Barristan Selmy, the King took certain liberties with Joanna on her wedding night. Of course, this has nothing to do with this theory since it was years before Tyrion's birth, but it does show that Aerys lusted after Joanna. Having said that, who is to say that the Mad King didn't eventually rape her, resulting in Tyrion's conception?
  • In the books, Tyrion has pale blonde Targaryen hair and not the golden color, like the rest of the Lannisters. Apart from that, he also has mismatched eyes which coincides with mixed parentage in Targayens.
  • He has dragon dreams, just like Daenerys, Rhaegar, and the other Targaryens in the past.