Louisiana
The Bayou State has a statute covering the broad aspects of tattoos and piercing. It has also adopted a number of regulations. Particularly, the regulations state that it is unlawful for ay person to tattoo any other person under the age of 18 without the consent of an accompanying parent or tutor of such a person. Persons found guilty of violating the provisions of the applicable section shall be fined not less than $100 or more than $500 or be imprisoned for no less than 30 days nor more than on year or both.
http://www.spcp.org/us-state-legislative-information/legislation-louisiana/