Spiders!

From the introduction: The party sits around the campfire, resting up from a hard day of questing and planning how they intend to handle their upcoming battle with the dragon. As someone reaches for another piece of wood to throw on the fire, the biggest spider they have ever seen scurries out of the hollow log. No big deal, right? After all, a party of hardened adventurers wouldn’t be scared of a spider, right? Even if it is the size of a small rabbit. Don’t be so sure.