Yes it's Hodir, father of those Sons that you hate grinding rep for. He is the lord of winter and has a mouth in his stomach. A nifty thing I thought was he may in fact be Father Winter. Since he is the lord of winter and the father of the giants, this could have easily been changed over the years to become the Father Winter that we hope gives us the right mini pet each year.
The fight is a combination of Saph from Naxx and the last boss in Nexus. You need to keep moving so that the frost dot doesn't stack up on you too much. A nice way to combat this is to stand by one of the cozy fires, this only applies if you are ranged. If you're melee, you're f@#$!d. Also remember that frost resist gear you were gonna get rid of, this fight is a lot easier with it and your OT is gonna have to have it when he uses his horn (OT with frost resist will need to taunt the boss so the MT doesn't take the frost damage). And he does flash freeze which you'll need to get onto the snow drifts (they form from the icicles that drop from the ceiling), if you don't you'll get frozen and you're raid will need to break you out of the ice cube. He also roots people so have mass dispel or hand of freedom is really nice for this fight.