The Golden card is called Marin the Fox and is presumed to be a character from the next card set due out in December. No stats or text have been provided for Marin, just the following piece of artwork:
The Hearthstone team had this to say about the reveal:
"Adventure! Danger! Derring-do! TREASURE! Meet Marin the Fox! Get a golden Marin with a BlizzCon 2017 Virtual Ticket."
Hearthstone's third and final expansion for 2017 will be revealed at Blizzard's annual BlizzCon fan-gathering, which kicks off this Friday evening.
Expect to learn the title, theme and new mechanics of the upcoming set. We'll also no doubt get our first look at a handful of the new cards coming to the game, followed by a reveal of the remaining cards over the next month or so.
We'll be covering BlizzCon throughout the weekend, so keep a close eye on the homepage from Friday evening onwards.