If you didn't feel a cold chill run through your veins at the sight of Daenerys's dearly departed Viserion's eyes turning that chilling shade of icy blue, then surely you are as dead inside as the Night King himself. The demise of one of Daenerys's dragons and his subsequent transformation into an ice beast for the White Walkers was undoubtedly shocking, and it's bound to have left a slew of viewers questioning just what can the ice dragon do. What are the ice dragon's abilities? And what threat do they pose to Dany, Jon, and the warm-blooded fighters of the Seven Kingdoms?
Well, George R. R. Martin may have left us a few clues in a story he penned in 1980. Martin wrote a children's book called The Ice Dragon, which tells the story of a young girl named Adara and – you guessed it – an ice dragon. Could Martin's '80s-era children's book give us any clues as to the scope of the reanimated Viserion's powers? Let's find out.
Long before George R. R. Martin introduced us to the world of Westeros, he tried his hand at a far less... inbreed-y story. In 1980, Martin penned a children's book called The Ice Dragon about a young girl named Adara who feels an affinity with the cold. She's the only person in her town who's not afraid of the ice dragon.
When Adara turns 7, fire-breathing dragons descend on her town, but the ice dragon manages to defend the girl and her family. The ice dragon defeats the invading firebreathers, but after the fight, he's nowhere to be found. All that remains is an icy cold pond that wasn't there before. A lot of readers think that The Ice Dragon is set in the same universe as Game of Thrones, but Martin has denied this. Of course, he's lied about book releases before, so who's to say he's not bluffing about this, too?
Even if The Ice Dragon is unconnected to Game of Thrones, there's no reason to believe that the same rules won't apply to Viserion's icy form: fire does melt ice, after all. That isn't to say Viserion isn't going to do some serious damage to Drogon and Rhaegal. The Night King launched that ice spear into the dragon's neck with incredible ease, and he got his desired effect instantly.
If Viserion is breathing ice—or the winter winds, or frost—he'll likely manage to land more than a few harmful blows against his former dragon siblings, even if they melt him into an icy body of water once the showdown is finished.
This may not be the first time an ice dragon has spread its wings in the Seven Kingdoms. In fact, the remains of another ice dragon may rest just outside Winterfell. After the ice dragon of George R. R. Martin's children's book was melted, he became an icy cold lake. A similar body of water is said to be on the outskirts of Winterfell; the pond in the godswood, near the Heart Tree, is said to always be cool. One Asoiaf.westeros.org user, BL00DoftheDRAGON, thinks this is more than mere coincidence, positing that the cool body of water could be the remains of an ice dragon that was defeated in Winterfell. If this theory is correct, that means the ice dragon can be destroyed.
If you're at all familiar with Game of Thrones fan theories, you're probably aware of R + L = J, the theory that suggests Jon Snow is the offspring of Rhaegar Targaryen and Lyanna Stark. Jon's parentage was all but confirmed by Gilly in the Season 7 episode "Eastwatch," so Jon Snow has fiery Targaryen blood running through his veins along with his icy Stark genetic makeup.