This is Netherspite Historian hs New Card to be released with the adventure coming on 11th August called One Night in Karazhan.
The card reads: Battlecry: If you’re holding a Dragon, Discover a Dragon.
The card is pretty weak at 1/3 for 2 mana, but the battle cry makes up for it. This is going to see play in a control dragon deck. There are plenty of powerful dragons that can make an impact on the game, and being able to discover a dragon that will help in the current game is a big deal.