Pictures Progression Of The Snow Walrus December 23, 2012 / 2:38 PM CST / CBS News (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS) Building A Walrus (credit: CBS)