I was thinking about hunting ground earlier and thought it would be neat if:
The area was set up where near the outskirts the critters spawn would be lower and would increase as you moved closer to the center. Either the spawn rate or critter difficulty could increase until you got to the `Queen` or `Chieftain`. The `boss` could be a rare spawn/elite style mob with maybe an increased chance for a special drop of some kind, maybe even requiring multiple people to kill.
Just kind of brainstorming here and apologies for the run-on sentences.