Board Thread:News and Announcements/@comment-408517-20140604185139/@comment-1512913-20140606142424

I've been speculating that perhaps within Narutoverse, there's besides humans and animals (which are technically the same but whatever) also Devas, Asuras, Pretas and Narakas.

I suspect that Kaguya may in fact be an Asura. This is what wiki says:

"The Asura realm is the realm of the demigods. They are here because of actions based on egoic jealousy, envy, insincerity, struggle, combat or rationalization of the world. They may be here because in human form they had good intentions but committed bad actions such as harming others. The Asuras of some inferior realms however, are malevolent (such as the corruptor Mara) and can be more closely related to the translation of demon that is sometimes ascribed to them" also: "they are plagued by envy for the devas"

So if Kaguya was an Asura, this would explain her hunger for power and her having eaten the fruit of Shinju (presumably a Deva) to attain true god-hood.