what is in a name??? a rose by any other name would smell as sweet...
uh, let me shut up. okay, tin nyanko's name really fits her. for you non-japanese speaking people, animamates roughly translates into 'metal animals,' which is why all the animamates have metals in their name, and they all have animals in their name. ^^b i.e. lead crow and heavy metal papillion (papillion is 'butterfly' in french).
now, anout nyanko's name. 'nya' is the sound a cat makes, and neko is cat, so when you combine them, you get nyanko. the tin is because all of the animamates have a metal in their name, which i had pointed out already.