George R. R. Martin's immensely popular series was around for 15 years before Game of Thrones graced television screens on HBO, and that gave fans a long time to forge some pretty strong theories. Many of those theories concern the parentage of key characters, promising surprise reveals about who's really related to who that would end up hugely changing the game (of thrones). Book theories and show theories don't always entirely track (the books offer a lot more background info) but they may prove important, so they're worth having a look at. Some speculation concerns Tyrion Lannister and suggests he might not be a Lannister at all. In fact, he might be quite a bit closer to the throne than that. Is Tyrion actually a Targaryen On Game of Thrones?
The Targaryens were the ruling family in Westeros for ages, but after the uprising that took the throne from them, their numbers dwindled. The most important Targaryen on the map these days is Daenerys, the sole surviving child of the Mad King, Aerys Targaryen. Then again, maybe she's not the only child of his left. There's a handful of evidence from the books that implies Tyrion might actually be the son of the Mad King, but you'll have to decide for yourself if that evidence is strong enough proof.
It was established that Aerys was a little too interested in Tywin Lannister's wife Joanna and even possibly assaulted her in some way on her wedding night, though the details of what happened are far from clear. That couldn't be the night of Tyrion's conception because he's the youngest child in the family, so whatever went on between Aerys and Joanna would have to have continued past that night for Aerys to be Tyrion's biological father. Tyrion's appearance in the books is also a lot more similar to the bleach blonde Targaryen look as opposed to the Lannisters' less edgy golden blonde. Hair color might not be a big deal in our world, but if you'll recall Ned Stark's forensic hair color analysis of the Baratheon spawn in Season 1, you'll remember that it plays a big part in Westerosi lineage.
There's also the fact that Tywin really hated Tyrion and even referred to him as "no son of mine." Now, there are a lot of reasons for this; it doesn't necessarily have anything to do with Tyrion literally not being his son. Tywin was a notably cruel man who hated any sign of weakness and he considered Tyrion to be a disgrace purely because he was a dwarf. Tyrion didn't need extra fodder to be a major a-hole, but that doesn't necessarily rule out that he might have had suspicions about Tyrion's legitimacy.
The more tenuous evidence involves Tyrion's fascination with dragons, a noted Targaryen trait — but really, who could blame him? Dragons are awesome. Then again, Targaryens must be "born of blood" and Tyrion's mother did die while giving birth to him, which is similar to both Daenerys herself and other potential Targ, Jon Snow. Daenerys, Jon, and Tyrion are often linked because they are three of the most important characters in the series, and because there is a prophecy told to Dany that concerns the "three heads of the dragon" — three Targaryens who are of vital importance going forward. They might just be Dany, Jon, and Tyrion.
Whether he ends up being a Targaryen or not, there's no denying that Tyrion is an important character who will likely end up playing a big role in the resolution of the series.