Clark County Washington categorizes Ball Pythons as a Wild Animal, requiring a special Wild Animal Permit. This permit is not required per animal, but can be obtained for $100 to cover multiple animals.
When receiving my permit, I also had to agree to a yearly SURPRISE inspection by animal control, which was very brief, and I recall the officer using the word “Impressed”.
The application for this is available at Clark County’s Animal Control web site, on this page: Clark County Pet Licensing
Just two years ago, when filling this application out, you had to agree NOT to breed. This requirement was removed in 2011.
A friend in Washougal, Washington, was visited by animal control, (due to a noisy dog) and was informed that while Washougal IS part of Clark County, the wild animal permit is not necessary there. I would personally look anyway, if I were under this jurisdiction.
There are also laws regarding transportation of animals across county and state lines, that might need to be investigated.
I do not offer legal advice, I am just sharing the laws as I understand them.