With Winter's Veil dropping on Wednesday, the Minion of Grumpus mount will come with it. It appears to be from garrison dailys 4 of them giving you 5 merry supplies which you can buy a savage gift with and it has a 1-5% chance to have the mount.
It also seems to not be a BoP, meaning it will probably be seen in trade of the Auction House.
I like this, I'm tired of the 0.5% holiday drop rate mounts.
Since it IS sellable on the AH, my tip is to wait until the last few days to buy it people! It will be cheaper then, dont buy it during the first initial rush it will be too much gold!
EDIT: Thank you my EU friends, it seems this mount is a 1-5%ish drop rate from the savage gifts, you get from doing all 4 dallies. And it also appears there is currently a bug where you can return the gift and keep checking inside if its in their. Will probably be hotfixed asap lol.
EDIT 2: The bug/exploit is now hotfixed in the EU. Some 3 hour bans have gone out for people who abused it to acquire multiple mounts.