GURPS Aliens – Nonhuman Races for Science Fiction Roleplaying, softback sourcebook, by Chris W. McCubbin.
“We Are Not Alone
In fact, every time we open the airlock, we meet a new race…
GURPS Aliens presents over two dozen new races for your campaign! Use them in any science fiction adventure…or fantasy, or horror. or, if you’re tired of throwing the same old metavillains at your GURPS Supers players, these alien allies, foes and technology will keep your game flying.”