In truth, worgs of various sizes are used by many different monstrous races. Some more intelligent races have bred different strains of worg, much like different breeds of dog; hobgoblins for example, are known to raise a large breed for themselves to ride, and a smaller breed not much larger than a common wolf for their goblin kin. Goblins on the other hand, simply ride on younger worgs until they become unmanageable, at which point they are either killed or chained up.