That anonymous individual who starts the office coffee machine in the morning, but at an hour so early as to avoid ever being observed doing so by co-workers. To everyone else, the result is a fresh pot of coffee that seemingly appears out of nowhere, as though it was prepared by fairies.
My mother always goes the lab early to prep the skin grafts for culturing and usually puts on a pot of coffee while she's there. One morning, a co-worker from clinical trials had to come in early as well, walked into the kitchen as she was scooping the grounds into the filter, and gasped in pleasant surprise, "It's you! You're the coffee fairy!"