Would it be illegal to kill an alien?

Would one be breaking any laws if they killed an alien (by which I mean extra terrestrials of the outer space variety rather than mexicans)?

Depends on the circumstances.

If it’s an animal by any definition, it very well could be.

Didn’t we already have one on this?

Hmm, two separate posts about the legality of humans shooting aliens made in a relatively short amount of time… Is there about to be an influx of gun-fearing extra terrestrials hitting earth soon?! Angry Lurker, what is your kind planning for the fate of earth?

That was an opinion post, this OP may actually be after hard facts.

[moderating]
Let’s just carry on the conversation in Oakminster’s thread (which Telemark linked to just above).
[/moderating]

ETA: Pan1, since we have no laws concerning shooting space aliens, it’s all going to be speculation anyway. If it suddenly takes a scholarly turn, I’ll have no objection to bringing it back here, though.