What do you mean it needs to arrive soon? Wtf. There are plenty of other legendary minions for other classes that haven't been revealed. So stop looking for an excuse to bash on paladin since you main 200 IQ cube lock. See you on ladder normie.
A huge meteor dropping on a city? Please be a Odd-mage spell!!!
Edit: I bet the gold version will look absolutely amazing!
To everyone thinking looks like a meteor: it isn't. It is a blood moon (i.e. the moon under conditions such as an eclipse when it looks red). Blood moons (as with full moons) have some association with werewolves (or worgen in this case).
Since half of the set is worgen based it is pretty hard to guess which class it goes to based on the image. The name 'Witching Hour' would be suggestive of mage or shaman except the art looks more focused on Gilneas and perhaps refers to the worgen going out to hunt in the witchwood as per the expansion's song.
So all in all I haven't the faintest idea what class it is in, but it does feel likely to be an epic spell and probably quite high cost.