The original sadly cannot be found, making the origin of the upload date and creator unknown, but many other stolen ones can be found scattered all over the web, making it still watchable.
The nyan is a Chocobo plastered over the original cat, so it is not based on the original sprite. A Chocobo is a bird from the Final Fantasy games.
The Nyan Chocobo flies through space, trailing a rainbow. The blue space background and exploding stars remain the same.
The nyan also flies to the Chocobo theme from Final Fantasy, a song known to get annoying to some of those who play the games.