Originally posted by mpanty
IThese are not pointless definitions... I'm no expert on this, so I don't know if an alien species could be classified as an "animal" if the case applies, but IMHO it does here.
IMHO, the Kilrathi are animals, and more specifically mammals...
I'd assume that you're correct in your opinion, but as you say yourself, they are aliens. They are also, as you say, aliens and our definitions apply only to creatures we've actually studied (so no aliens officially then).
The animal definition is incredibly broad, so that doesn't really help us.
The vertebrate definition is very clear, you have vertebrae, you're a vertebrate, end of discussion. If Kilrathi have backbones, we can call 'em vertebrates.
To call the Kilrathi feline would be inaccurate, as that relates to terran cats. We could say that they have feline characteristics, but nothing more specific than that as they are not, in any way, terran cats, or related to them. Unless there's something we're not being told.
To call they mammels would also be inaccurate without extensive knowledge of their biology. To do this assumes that they can control their temperature in the same manner as us, suckle their young in the same manner, reproduce in a similar manner etc...