I'm assuming the 'NC' in your location is North Carolina. I did a little looking around on your states Game and Fish site
http://www.ncwildlife.org/
Under 'License * Permits * Registration * Titling' is an option for 'Other Licenses and Permits'. Down at the bottom of that in the 'Wildlife Possession' box is an option for a license for amphibian ownership. It says it's free, but it also says 'native species' but it's the closest I could find since under nuisance species they don't have an option for amphibians. You might try calling or e-mailing them for more information on the subject. I'm sure they can help.