Here Kitty, Kitty!

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 .