Over the last 50 years (giver or take) one of the most commonly used
alien archetypes are Cat-people, call them Alslan (Traveller), Kilrathi
(Wing Commander) or Kzinti from both novels and (Star Trek) and a host
of others. They all have several traits in common with Earth felines besides
their obvious resemblance. The Pride/Clan social structure seems to be the
most common form of government with a monarch of some type at the top
but he/she is still very much subject to how the clan leaders feel . They are
usually quite xenophobic and territorial. Their technology is usually on par
with humanity with some unique culturally old tech weapons held on to, just
because. This of course makes them interesting and fun to run. They also
in many cases, (perhaps due to their clan structure) quite often go rouge
either as an individual or up to an entire clan. Often this can be as a means
of credible deniability for their central government or they just got pissed
off by someone or something. All in all this give you allot to play with in
any games system....And they look cool .