The PCs are tramping through the countryside, when one of them notices that there is a rabbit following them, about 100 yards back. Whenever they try to approach it, the rabbit flees. Nothing they do will keep it from following them. If killed, it is replaced by a rabbit bearing different markings. After a few days, they notice that now they have TWO rabbits following them. Then three. At no point should they be followed by more than 3 rabbits. They soon come upon a town of halflings, who at some point inform the PCs that all of the "trackers/hunters" of the town left a while ago, on a monthly food-foraging trip, but that they are expected back within a day or two. After spending the night in town, the PCs wake to fact that they have been robbed of all monies! No other items were tampered with, except those that contained money, of which all money is gone. Come up with a way for the PCs to get their money back, shortly after which, a runner comes into town shrieking "The trackers are all dead!!!" After calming the runner, he will say that the trackers should have been back by now, and that they are certainly all dead! (Now all this time, the Inn in town has been serving a rabbit stew to all of its patrons, because that is the only game that the non-hunters could catch, and all other food sources are depleted, which is why the hunters are out hunting! (heh heh)
The rabbits ARE the trackers/hunters, after being polymorphed by a mad mage living in the hills around where the hunters were hunting. They intruded upon his land, and he enacted an amusing (for him) vengeance upon them. yes, the PCs get this info, after going looking for the hunters the villagers remaining are VERY generous with offers of rewards, finding the wizard, and reading his notes after the battle.