I wrote on a coworker's banana today, with the tip of a pen cap, very lightly....so it would bruise very slowly over the course of twenty minutes or so... and form three creepy little 6's.
An hour after the carving, I heard her gasp and yell "OH MY GOD!!!!" And she came running over asking if I did it. I responded, "What is that??? Is that the Mark of the Beast!??"
She yelled, "TELL ME!!! I'm still shaking!!!!"