There's a disclaimer.
"Creating a tattoo is an art, therefor, you hereby grant artistic license to the person creating your tattoo. You agree not to sue us because you have your head up your ass and don't REALLY know what you want marked permanently onto your body, and therefore, you want me to "do something like this". Sign below....NEXT TO THE BIG X YOU DUMMY!....stating that you understand these terms and agree to them."