Humans learned the art of tattooing, (among other decorating arts of the body,) from the fallen angels that mated with human women before the flood of Noah. (http://www.eaec.org/bibleanswers/Noah.htm) Indeed, an increase in tattooing is a sign of the end times, because so many were doing it in the pre-flood days of Noah. It would not surprise me if the mark of the beast might one day be noted with a tattoo.