In the previous version only cats with "tabby" variation named "Niko" spawned as one. In this version this have been fixed and now all cats named "Niko" are able to spawn as Niko.
Due to an error which i have made only cats with "tabby" variation was able to spawn as Niko when named as one. This have been fixed in the next version, so if you need all cats named "Niko" to spawn as one go see the Nicko Pack 1.2(all cats) version