What I don't understand is why in order to qualify as SF, one MUST
have non-humanoid aliens in large numbers? (You already mentioned Kosh
and n'grath, that's two.) Leaving out the practical side of the
argument -- that actors are (generally) human, and if you want ANY kind of
characterization, you need an actor, animatronics aren't generally at the
level yet that can give solid long-term performances -- the argument seems
dubious from a scientific point.

To become a spacefaring race, one has to go through some measure of
evolution, avoiding becoming prey, and becoming adept at making tools,
using fire (or its equivilent), and so on. From the biologists I've
spoken with, the species with the best chance of survival are those with
their sensory equipment at the highest point of their body, for instance;
as with humans, that puts your eyes, ears and scent organs at the top of
your body. To avoid predators, you need legs, at least two. Four is a
possibility, but aren't as suited to handle difficult terrain or squeeze
through narrow openings. To ward off predators, and build devices of a
technological origin, you need forelimbs, minimum two, and given that the
universe tends toward bilateral symmetry, you'll probably get pairs. And
an opposible thumb (or other similar appendage) is certainly useful as
well. What you get is something fairly humanoid.

(As an aside, it's interesting to note that in all tales of UFO
encounters -- and I'm not taking sides in this, just dealing with the
subject -- the aliens aren't huge lobsters or insects, they're fairly
humanoid.)

You can have a character who can relate to our characters, show
emotion, carry on a long story...or you can have puppets. Choose one. I
know there was Yoda (on whom was spent VAST amounts of money, and time
that is only available on film projects), and that was well done, but
even that was clearly a puppet. The technology doesn't yet exist to do
what you ask. You might as well say, "It's not SF unless Straczynski is
able to fly around the room on his own power." The resources to do it
aren't here yet.

Nonetheless, we're continuing to try and find some ways of doing
this. There's a *very* non-humanoid creature in "Grail," created by CGI,
which is about 60-70% of what you got in Jurassic Park. It's a start.
Maybe in another few years, we'll have the tech to do more of this. But
for now, it's not good enough to do the job *convincingly*, and I'd rather
not do it than do it badly.

jms

Okay, but then you're going to have an actor trying to emote in
scenes with an air-breathing octopus. It's going to look *silly* because
the tech doesn't exist to make it look REALLY good. There are some things
that work in fiction, and some things that won't work when you have to
FILM them. This is one of them.

jms