Country Cats: Nyans which are cats or other animals and are based off of a country. Nyans based on cities, states, or provinces should instead go on the "Around the World" category.
The Nyan Cat Countries videos are different versions of Nyan Cat that have been customized to represent different countries. The videos usually have alternate music from the original Nyan Cat viral video to fit them.
Around The World is a Nyan Cat series which contains lots of variations of Nyan Cats which relate to countries or other places.
Above are some examples of them, but there are loads more. Greek Nyan Cat, American Nyan Cat, Chinese Nyan Cat, the list just won't end! Many can be found on the Wiki, so be on the look out!