i think it would be really spiffy if piggies got scared and ran away when you made a grr face at them. not necessarily all the way to another zone or anything (although that might be interesting too!), but at least they could get a bit startled and run away from you in the opposite direction. it's a bit unnerving to go RAR in a piggy's face and to have them respond with that cold, unresponsive gaze. :)