A relentless and unearthly durable type of dimensional fatigue 'denizen'
It's always the creepy little kids
They came upon us suddenly, no sound preceding them until the splashing of their feet drew our eyes towards them. The wolf-things neither howled or snarled as they tore into our ranks.
A powerful wizard that the PCs encounter is completely silent. He does not speak and cannot be heard as he moves. Even his spells are silent, but his magic is just as potent.
He has a tendency to summon invisible chairs, place foes in invisible boxes of force, and other "mime tricks".