Outside of my city, there is an apple orchard, with a small cemetery at the end of it with only about 5 or 10 graves in it. If you visit the cemetery, it is customary to leave a small offering by the largest headstone, even an apple from the orchard will do. If you do not, every night you go to sleep that week, you will see an old man in your dreams.
On the first night, he will appear to be a normal balding old man. He will tip his hat to you and walk away.
On the second night, he will have a knife in his right hand. He will tip his hat to you, and walk off once more.
The third night, he will lick the knife, and laugh, before disappearing.
On the fourth night, he will appear closer to you than before, and lick his knife once more.
On the fifth, he will be practically on top of you.
On the sixth, he will appear as a skeleton dressed in rotted rags, still holding the knife, still making the licking motion.
No one knows how long this continues or how it ends, the victims have all either gone back by then and made an offering, or they have died of heart attacks in their sleep.