The stone the mysterious stranger left look just like the regular wishing stone, but it wasn't. Its color was a sickly shade of green.
It was the Sniffling Stone. Wishes worked just like the normal stone, except it caused the wisher to start sniffling and sneezing. The more wishes they made, the more their nose would become runny and they'd sniffle and sneeze. It gave them the symptoms of a cold.
Worse, if used more than ten times in a single day, the user would basically develop flu-like symptoms.
Jon awoke that morning not knowing the stone next to his bed was not the original stone, but the Sniffling Stone.
