I…just don’t know how to better expound upon the question, beyond the title. (Chalk it up to a personal failing, or the lateness of the hour.)
Stunning question.
I can’t add anything more than that.
Excellent question. Just what I needed. Let’s see. Jewfaq.org defines the basic rules as follows:
I think we can safely assume that no extra-terrestrial creatures are on any lists of forbidden animals.
If the E.Ts can be defined as birds and/or mammals, we’ll kill them in the proper way. Easy enough.
Provided the E.Ts have blood, this is also easy enough to do.
Either the E.Ts have these parts, in which case we don’t eat them, or they don’t, in which case there’s no problem.
So we won’t mix E.T flesh and dairy, to be on the safe side. Great.
No problems here.
There are some additional rules. One says creatures that live in the water cannot be eaten unless they have both fins and scales, for example. But in general, it appears God had the foresight to make His rules clear enough that they can be successfully applied to extra-terrestrial creatures. I am eagerly awaiting zev_steinhardt’s response, though.
I’m not zev (and I’m not even religious), but somehow the bit about mammals being kosher only if they: 1) Chew their cud and 2) Have a cloven hoof got lost along the way.
For instance, according to your list above, there is no reason to forbid pork…
Marine animals must have both fins and scales (which is why lobsters and shrimp are not kosher - end of Religious vs. Atheist debate for me, right there :))
Also, while birds are forbidden on a list basis, rather than a set of rules, IIRC all birds of prey are considerd Treifot.
So - It had better be an herbivorous E.T., unless it’s a fish (it’s very unlikely a mammilian carnivore would regurgitate in any environmental conditions found in the universe); and it would have to look quite a bit like a cow or sheep or a fish or a chicken to qualify…
As an aside, it may be quite difficult to determine whether a given animal is a mammal, bird, or something completely different for which we have no rules… (think of an ET from someplace with no mammals trying to classify terrestrial dolphins and whales)
Yes, there is. Point 1. Certain animals may not be eaten at all. Pigs are among those animals.
I disagree. Appearance rules aren’t found anywhere as far as I know. Cloven hooves, cud-chewing, fins, scales and the like are described, but those could very well exist on extra-terrestrial animals.
I don’t think it’d be all that tricky. We have set rules for mammals, birds and the like. If something fits the mammal rules, it’s a mammal. If it doesn’t, it isn’t.
Something tells me that either way it would definitely be suicidal.
Late addition: the cud-chewing rules are in fact appearance rules of a sort. Some non-cud-chewing animals are listed as cud-chewers in the Torah because they make the jaw movements characteristic of cud-chewers.
Well, Rabbi Koslov on Babylon 5 figured that extraterrestrial fish was kosher, although he hasn’t issued a ruling on spoo yet. 
I think Priceguy has it right: if these E.T.s are land-dwelling animals that have cloven hooves and chew their cud, or sea-dwelling animals with fins and scales, then presumably they would be kosher.
[If they fly, it’s more complicated than determining whether they are carnivorous. Strictly speaking, as long as they’re not among the twenty-four non-kosher flying creatures listed in Lev. 11:13-19 and Deut. 14:12-18, they should be permissible. In practice, though, because of various considerations - one of which is that the precise identification of many of these species is doubtful - we eat only birds that have a tradition of being kosher (e.g., chickens, ducks, geese, turkeys, doves, and quail), so unless there are Jewish “little green men” out there with such a tradition, they would probably remain forbidden.]
That said, I have to wonder whether these rules would be relevant in this case, since in Lev. 11:2, the Torah introduces the rules with the expression, “These you may eat from among the animals that are on the earth” (although there is no such phrasing in the parallel passage in Deuteronomy). So it might be argued that these rules are meant to apply only to creatures dwelling on this planet! (Which could be taken either way - you might argue that this means that extraterrestrial species are unconditionally permitted or unconditionally prohibited.)
Add in the points that kosher animals are neither scavengers nor predators. Also, kosher land animals tend to be herd animals, and easily domesticated. (Although it’s been commented to me before here in GQ that giraffe are hard to domesticate.)
In my book (and I admit that I just went into IMHO here), a creature sentient enough to develop language skills is not kosher. I developed this opinion the last time I watched the H2GT2G series, in particular the Restaurant at the End of the Universe dinner scene.
My take is that the rules of kashrut will need to be applied carefully once we discover edible extraterrestrial species.
This is a new one on me. I knew about no dairy/meat … but no meat/bread or meat/veggies? Then what the hell is going on with the gajillion Kosher Delis in this city? How can you have a Pastrami on Rye? Or a Kosher Hot Dog?
Umm, toadspittle, I think you should read a little more closely. It says that vegetables etc can be eaten with meat or dairy.
Hmm. It seems to me that while this practice makes sense for earth animals, it’s pretty clear that none of the birds listed in the Torah are extraterrestrial birds. So it seems to me that all such birds should be allowed.
Doh! I assumed it was only listing prohibitions. My bad.
Forget about that…the important question is, Is the R-strain kosher?