I found a useful article from Nendonesia website. A very useful article with images to teach you how to further identify fake or bootleg Nendoroid. The most obivious parts of bootleg are still shiny skin tone and irregular size. However, beware fellow collectors. The quality of bootleg are improving especially Kuroneko !!! So, becareful while purchasing a Nendoroid.
More Bootleg Nendoroids (Link to 3rd party website)