Magical Tattoos of Thailand’s Mahouts: Elephant Trainers of Ayuthaya by Lars Krutak:
Generally speaking, there are three classes of tattoos that can be received at Wat Bang Phra: those that act on others, causing them to like or fear the bearer; those that act on the bearer, increasing his skill with words causing the listener to do as he asks and instilling him with courage; and tattoos that create a protective barrier around the person that prevent animals of all sorts from biting, knives from cutting, bullets from entering the body, and fire from burning the body. Magical tattoos, whether for these or other purposes (e.g., for eternal health), are in a sense like preventive medicine and can be thought of as kinds of vaccinations against various diseases and misfortunes.
via plsj