It's a very, very cold shotgun.
Upon using the Snow Barrage, it will fire up to 5 sets of 4 snowballs, making that a maximum of 20 snowballs per use. The item fires very fast to very slow, only firing again after the previous set of snowballs hits a block or a mob. Each snowball does 4.25 hearts of damage.
How to Obtain
This item can be found in the Present Chest