Chapter 578 - Kit Kat

There is absolutely an absurd amount of Kit Kat flavors out there. Taken straight from the most reliable source of information, Wikipedia, "There have been more than 300 limited-edition seasonal and regional flavors of Kit Kat chocolate bars produced in Japan since 2000."

(The actual source is from a CNN article from 2012, however there they only mention over 200 special edition flavors)

Whatever the case, the article is almost a decade old so the actual numbers might be significantly higher.