When I first read this fan theory on the internet, I thought whoever came up with it must’ve been crazy. But that was before I read the books, my friend. And while there isn’t much supporting evidence in the TV show, there definitely is in between George R.R. Martin’s gore and food descriptions. I decided to compile all the evidence I could think of, and well, there’s a lot. See for yourself.
George R.R. looooooves him: I know that technically, this doesn’t count as concrete evidence supporting a theory, but I’m trying to lay ground work. Tyrion is arguably George R.R.’s favorite character in the whole series. You think that someone who has unveiled such creative backstories and plot twists about so many characters is going to make his favorite one exactly how he appears?
Aerys had motive and opportunity: So if Tyrion is a Targaryen, that means that Aerys, the Mad King, is his dad, and Joanna Lannister is his mom. Theorists frequently point to Aerys’ infatuation with Joanna and his hatred of Tywin. Maybe the combination of these motivated Aerys to rape Joanna. Considering what a psycho Aerys is, this is very plausible. If it happened, Tywin would highly likely know. This would explain his disdain for Tyrion. Aside from his last words being “You’re no son of mine,” he also, when his son asked for his rights to Casterly Rock, told Tyrion this:
“You are an ill-made, spiteful little creature full of envy, lust, and low cunning. Men’s laws give you the right to bear my name and display my colors since I cannot prove that you are not mine. And to teach me humility, the gods have condemned me to watch you waddle about wearing that proud lion that was my father’s sigil and his father’s before him. But neither gods nor men will ever compel me to let you turn Casterly Rock into your whorehouse. Go, now. Speak no more of your rights to Casterly Rock. Go!”
Although I find Aerys’ relationship with Tywin and Joanna, and Tywin’s disdain for Tyrion are evidence in favor of Tyrion’s Targaryen roots, I don’t think this suffices alone as definitive proof. (A lot of theories stop here, essentially, but this evidence is not the most convincing.) It is possible that Aerys’ feelings never amounted to anything, and while Tyrion being a Targaryen seems like a much more probable reason for Tywin’s hatred than simply that Joanna died in childbirth (Lyanna died in childbirth, and Ned didn’t hate Jon), on it’s own, this isn’t enough. It can be explained away.
Tyrion is not cursed in the eyes of gods and men: That’s the fate of kinslayers verbatim. Forever cursed. And curses are not just a saying you can take lightly. The Frays are cursed because they murdered their guests at the Red Wedding, and you see the curse take effect. Stark sympathizers and Brothers without Banners alike hunt them down, they’re plagued by bad luck and wolf attacks, and even their allies don’t like them and/or don’t want to spend much time with them. (I’m also convinced that the aforementioned curse is what brought Catelyn Stark’s zombie/Lady Stoneheart to life to kill Frays.)
A kinslayer is just as damned, but have we seen any hints that Tyrion might be cursed for murdering his own blood? On the contrary, Tyrion is exceptionally lucky. If he really was cursed, Tyrion would have died at the beginning of A Dance With Dragons, when he was depressed and binge drinking (binge drinking more than usual, that is). But he’s alive and constantly lucking out of perilous situations. Either the universe forgot about his crime, or he’s not cursed because he’s not a kinslayer.
Besides, as stated above, George R.R. loves Tyrion. Would he really doom him to be “cursed in the eyes of gods and men”?
He doesn’t get greyscale: In the show, this is explained as Tyrion lucked out and didn’t actually get touched by a stone man. But the books are a different story. Tyrion gets grabbed by the face and yanked underwater for quite some distance by a stone man, swallowing stone man water, and Griff dives down and saves him. Tyrion is told to prick his fingers and toes to check for greyscale, and he does throughout A Dance With Dragons, but Tyrion never contracts the disease. Meanwhile, Griff — who, while still touched by a stone man, was much less exposed than Tyrion was — starts showing symptoms of greyscale right away.
The Blood of the Dragon carries immunity to a lot of diseases, including greyscale for many Targaryens. Yes, it’s possible that Tyrion does have it and the disease is just taking a while to manifest (one maester tells him it could show up at anytime), but I personally think he’s in the clear. Tyrion could have been immune by happenstance, but when has something that has ever happened in this series been a coincidence?
Or the pale mare: This is an entire subplot that doesn’t make the show. But in A Dance With Dragons, Tyrion is sold into slavery and works for this very wealthy Yunkai guy as his servant and dwarf performer. (Other important detail: Tyrion earlier in the book met a dwarf named Penny who performed at Joffrey’s wedding, and they roll together for the duration of the book. They’re sold into slavery together as a dual act.) The Yunkai are camped outside of Mereen when the plague the pale mare hits. Tyrion’s master gets it, and Tyrion and Penny have to take care of him until he dies. But while Tyrion is exposed up close and personal to the plague, he stays healthy. (Penny, on the other hand, starts to show pale mare symptoms at the end of the book.)
This one is more convincing than the greyscale, in my opinion, because Danaerys herself acknowledges that as a Targaryen/Blood of the Dragon, she is immune to the pale mare. (She goes outside the city to visit the sick, who are quarantined, holding hands and such despite warnings from Ser Barristan, and she doesn’t get sick. She also says she’s not worried about getting sick because she’s immune.)
But he doesn’t appear to be a Targaryen on the show! This is a fair argument. (I like to use the show to predict the book’s future, though they don’t perfectly align.) (Hold the Door, R+L=J and Shireen’s death were all spoiled on the show). And while the show has strayed away from the books, would they really ignore such a monumental plot twist as Tyrion Targaryen? The show has the same final destination. So if Tyrion is a Targaryen, his final destination involves riding one of Dany’s dragons. As a bastard, he wouldn’t have claim to the throne, but he probably would get a nice sum of land (maybe Dragonstone or Casterly Rock?) and would likely be Dany’s hand or at least sit on the small council and use his brains to help his true family. On the TV show, Tyrion’s fate is not much different. We don’t know if he will ride a dragon (that’d be dope though), but if Dany is queen, he will be her hand and would probably rule Casterly Rock also. The end result is the same, so Targaryen heritage is not really outside the realm of possibility.
Conclusion: Any of these facts alone is not enough to prove Tyrion’s Targaryen heritage. But all of these hints added together is too much to be random. Not with someone as calculating as George R.R. Martin. The only question left is how do Jon and Tyrion decide who will ride Rhaegal and who will ride Viserion?