Sliding on snow and ice is nothing to a walrus, so they aren't satisfied with relying on mere gravity. That's why he made a snow box from a converted space shuttle. 1,225,704 pounds of thrust would be too much for many creatures, but the thick skull of a walrus can handle anything.
Note the handy bucket storage rack.
Due to the Orbital Maneuvering System pods it's surprisingly nimble; 360 degree turns are possible! Thus this is the sled that will run rings around the rest!