I love goblins and lizardmen. Goblins because deranged little dudes running around is always a blast. Lizardmen because alligator people with melee weapons are the way I wish dinosaurs evolved instead of being birds.
Interesting use of terms. In Discworld Dwarven society, being lowborn would be a good thing and while being high born is only one step below surface dweller. The dwarves are ruled by the Low King (or Queen). The lower you are, the deeper you are in the mine, and the more rich and important you must be.