In case you just hopped on the MMO bandwagon with the release of Star Wars: The Old Republic, it's not a massively multiplayer party until the anthropomorphic animals arrive. The original EverQuest had the Vah Shir, World of Warcraft has Worgen and now Pandas, and The Old Republic has the Cathar, a race of intergalactic kitty people.
It's difficult to pinpoint exactly where the Cathar first appeared in Star Wars history, mainly because every time I try to search for them, Google is busy looking for "catharsis." The most famous gaming Cathar is Juhani from Knights of the Old Republic, a Jedi member of a Cathar sub-species that doesn't look quite as furry as the ones we'll be playing now.
The Cathar are fierce warriors and incredibly loyal, so if you're going to roleplay them having sex, don't be slutty.
The Cathar are available as a player character race with today's game update 2.1 for The Old Republic, which also adds all sorts of dyes and new customization options. Hooray!