I watched this video. A network of pipes blows air at the bottom of a bathtub filled with sand. The sand behaves just like water. Objects can float or sink in it. Children can play in it.
So, my creature is worm-like. It has a snorkel which it holds above the sand to suck air. The creature has many vents which blow the air in the sand, both around and in front. The sand around the creature becomes fluid-like (quicksand) and the creature can swim in it.
Is that a feasible way to swim in sand? Can larger creatures like the worm from Dune series swim this way? I still think the creatures must find a way to keep their snorkel above the sand at all times, or else they risk inhaling sand into their lungs.