Anyone of Arab or middle east muslim ancestery. Derivitive of the slang term "Sand Nigger." "Dune" comes from the large desert regions and spook from the slang term for blacks.
Dune beast is the term given to a person who has just been given a "facial" and had their head rammed into the sand. The sticky residue left behind from the facial leaves the sand stuck for hours
5 bucks says you can't turn that hotty into a dune beast