A shadow is 5 to 6 feet tall and is weightless. Shadows cannot speak intelligibly.
...Third, while the NWN handbook states that Shadowdancers travel in troupes, I've never once seen a Shadowdancer troupe (largely because there are so few of them on the server.) If they had a druid-like hierarchy, or actually traveled in groups, I could see the justification for a private, Thieves' Cant-style language, but since a number of the Shadowdancers on the server are largely loners, I can't see any justification for an automatic granting of such an ear....
Example -Three people are having a conversation. Shadowdancer A, Shadowdancer B, and Fighter C.A: So, what did you say you saw?C: I saw the beholders leaving the Cave of the Eye! I think they're gone!B: What do you think, A? *tapping her fingers on her left elbow, idly*(A's player knows that left elbow indicates falsehood, while tapping indicates conversation subject, so B has just conveyed to A that she thinks that C's lying.)The beauty of something like this is that a) it's truly exclusive, and b) You can make it unobtrusive, unlike Thieves' Cant, which is ridiculously obvious even without the "X is now using Ear for Thieves' Cant". If you spend enough time codifying the "language", an entire secondary conversation can occur that a third party is not even aware of. *grins*
It's important to remember also that Thieves Cant is not a conversational language...at least not in the sense that it can convey long, complex thoughts.It's intended for things like "Easy mark at the bar" or "That one is the police" or similar things.
A question about shadows: Does this mean that ANY of the Shadows are not undead, i.e. the Shadon summons?