Probably something gotten from Fishing, for sure.
There was a lot of DK debate, but apparently it's just a tooltip fix as confirmed by a Blizzard blue.
Anyone on the PTR Looted the gill and can give some insight as to want it drops?Ugh hope its not a cooking Recipe or so vendor gray that is named something like Salt Water.
The Death Knight change is not actual change, it's a tooltip update. Confirmed by blue post recently.
I'm interested about this Water-filled thingy, the Item Level suggests it isn't a new Bag of Fishing Treasures, but who knows?