"Minor" is in fact a term with a legal definition and ramifications. Age of majority in most states is 18, save for a few odd balls. A 30 year old still living with their parents is still a 30 year old, legally an adult and responsible for the the cost and care of their pet. If they want a snake, but their parents don't, they can bloody well get a job, a room mate and their own place. Kids as young as 14 in some states can be tried as adults if the crime is heinous enough, and they are determined to be in full control of their sanity, and demonstrate they knew what they were doing at the time was wrong/illegal. That has no bearing on them being able to move out of their parents care or be held legally responsible for signing a contract or care of any animals in that house hold. If your kid sneaks in a pet then neglects it and animal control/ASPCA find it, guess who's gonna be held legally responsible for fees or jail time? Hint: not the kid.