There is a small and strange nature-worship cult that has dedicated itself to freeing vegetables. They appear usually in working pairs or trios, arriving to villages and towns separately and wearing the local garb. For some reason, they have taken to disguising themselves specifically as a scholar, a cooper, and a fisher. At night, they will sneak into backyards and side gardens, digging up household fruits and vegetables. They pile the pilfered plants into a cart and vanish in the night. While the townsfolk wake up to empty gardens, the cultists replant the fruits in the wild to let them be "free".
Gnomes are famous for their festive springtime celebrations. Farm villages will often dye their hens eggs bright colors; with gnomish magic, the chicks that hatch from the eggs have the very same colors. The chickens eventually lose their hues, but the stronger the magic, the longer the color stays. In a gnomish village, one can easily spot the village shaman by his flock of gaily colored fowl.
Rich Romans raised fish in private pools at their villas. A favorite fish was lamprey, a parasitic fish which sucks off blood and flesh but made an excellent meal. A particuarly gruesome punishment for slaves was to be thrown into the lamprey pool, where their flesh was ripped from the bone by swarms of the jawless fish.
In ancient Rome, social appearance and respectability were everything. The most hated men were punished with damnatio memoriae, damnation of memory. Every trace that a person had ever lived was removed. Busts were shattered, freizes were marred, records were struck. Any sign of the hated figure was destroyed.
Medieval Britons didn't write contracts. Instead, men making agreements would clap their knives onto an altar and recite the agreement three times to seal a deal. Even after the Normans introduced written contracts, British nobles would wrap the parchment around a knife to authenticate it.
In nature, for instance, a rhino has flies and ticks etc, that live on the hide and live off the blood. Rhino will visit and lie in ponds where turtles will clean the underwater portion of the ticks and a species of bird will clean the the top of ticks and other parasites. What if where the characters camp there were a species of animals that lived off wounds of the creatures. PCs camp. Anybody with wounds on there body are soon covered with small rodent - insect - shadows - whatever. Would immediately see it as a threat I would imagine. But perhaps one of the wounded didn't wake up when it happened, and when they did finally wake they were completely healed. Perhaps somebody was warned of something attacking them but they were able to notice that the wound was actually getting smaller instead of larger. Or maybe they successfully beat the creatures off them and don't notice an improvement, marking this place never to rest at ever again....later learn that villagers send their wounded there but they keep it a guarded secret because they don't want all the attention or traffic and what comes with such a special gift. Could turn into something more too if characters decide to start blabbing about it.