"Game of Thrones" is known for its utilization of dragons. In their history, dragons lived a long time ago, before they vanished in the land of Westeros. Now, in the upcoming "Games of Thrones" season 7, fans speculate that the undead dragons are going back with the White Walkers.
The White Walkers are the undead roaming in the cold behind the wall in castle black. With the ability of the Night's King to bring dead people back, it is not impossible to think that they can also do such thing to other living things like the dragons. These dragons are a very big help when they conquer the Westeros that might happen this coming "Game of Thrones" season 7.
The only dragons that surely appear in the "Games of Thrones" season 7 are the dragons of Daenerys. No clues or hints were given about the speculations of undead dragons, but seeing the Night's King riding a dead horse makes the fans think that it possible that the White Walkers could be riding dragons.
A report from Inverse cited a big spoiler for the series. It says that in the "Game of Thrones" season 7, one of Daenerys' dragons, Viserion, will be killed in the Westeros battle and will be resurrected by the Night's King of White Walkers and will use the blue-fire breathing dragon as the Wall-destroying undead's ride.
Now, as Daenerys' dragons are all still roaming in the latest books of "A Song of Ice and Fire," we have no precedent to base this rumors off. Some rumors from fans also say that the dragons are not only expected to come with White Walkers in the "Game of Thrones" season 7, giants and other mythical creatures might also appear.
Though there are issues that the upcoming season will be delayed, the "Games of Thrones" season 7 is expected to air this summer of 2017 with less than ten episodes unlike it usually has. The series is expected to end on its 8th season.