Specifically among those imprisoned under the Gulag system of the Soviet era, the tattoos served to differentiate a criminal leader or thief in law from a political prisoner. (Photo Russian Criminal Tattoo Encyclopedia Vol. Since snakes are both feminine as well as masculine, snake tattoos are worn by both the genders. Skulls generally designate murders. EDIT: This website mentions a crucified snake on a cross. The snake is also an Occult representation of Satan, though they may not call him that. Some Dark Moon Goddesses were depicted, with snakes as hair. If it is a cross, I'm not sure. He has dozens of names that different cultures call him by. //