Very nice, but I'd be afraid of *everything* in your campaigns, Vorpal Tribble. Trees... rocks... streams... roads... dreams... EVERYTHING is potentially hostile!
The trick is to foist things off on them like this in the beginning... and then gradually stop introducing them till you never even actually have to do anything. They'll be freaking themselves out. Mind games are so much more fun than encounters...
For example, I love this little encounter here with two of my players. Basically they are just venturing out of a town ringed with a wall...
As you converse the mist thickens into a peasoup a man could drown in if he took too deep a breath. The world around you shrinks to a personal space that hardly extends twenty feet in any direction. Several minutes into your talk a *clunk* comes from overhead nearby, easily heard, though out of sight in the fog, followed by some random thumps and clankings.
"Whoa," Chesae whispers sharply, gesturing the dogs to halt but at the same time cautioning Kramus. Chesae lifts his bow from around his shoulders and stares hard into the thick mist, trying hard to discern the source of the noise.
Kramus stretches his arm towards the crossbow secured to his backpack, which now rides the horse in his place. Damn! Won’t be much use if I can’t see beyond my own nose, he thinks to himself hesitating. With a frown he makes up his mind and arms himself with the crossbow, keeping his staff close at hand. At least I’ll get one shot off, ”Hopefully I hit something,” he mutters quietly as he trains his crossbow towards the noise.
[OOC: Readying an action: shoot at anything that comes into view looking hostile]
There is a creaking, and a moment later a *clink* *flash* *clink* *flash* *clink* *flash* of light up within in the mists from where the sound is originating.
"What...? What the hell is going on?" Chesae whispers to Kramus. "Have you seen anything like this before?" Chesae nocks an arrow then ducks low, aiming his bow upward and awaiting the cause of this strange display.
[OOC: I will also ready an action to shoot at any apparently hostile target that comes into sight, in addition to appointing the target for my dodge bonus]
Not taking his eyes from the strange sight ahead, Kramus replies, ”That a fog would so hastily concentrate about us seems unnatural. I know of magic that could produce such an effect.” He thinks for a moment before continuing, ”Generally the area of such magic is limited, which would allow us to simply walk from the fog. However, at the moment we are equally hidden from them as they are from us. I rather like it that way.”
"Hm... agreed," Chesae whispers back over the noise above, waiting for who-or-whatever it is to pass or reveal itself.
The spark flares up and light spreads out to partially illuminate the wall surrounding Chaunelfiel upon which the flickering foglamp sets. A shadowy figure on the other side closes the lantern with a familiar squeak of hinges. It then climbs down whatever it is he was standing upon.
[OOC: boy is my face red]