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.
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.
An old, misanthropic and paranoid man feels his time is coming. There are sons to leave his fortune to, but they are not worth it, not a dime do they deserve! And he doesn't really trust anyone else. And so he has made a decision: as a part of his last will, his henchmen are instructed to burn and destroy all his holdings, buildings as harvest. The lands shall be auctioned off, the proceeds used to pay the servants. Nothing shall stay behind. Nothing.
Depending on the status of the grumpy old man, this weird occurrence may be only a family drama, or it may end up bringing an entire region into chaos. Or the son(s) have found what should happen, and want to prevent it before their sick father dies.