From publisher blurb:
Close Encounters of Every Kind!
Whether you’re encountering them on a distant planet in a far-off nebula, or they’ve come to you, and are abducting innocent villagers for nefarious purposes, there’s nothing quite like a strange, alien race to help breathe some life into your galaxy—and your game. Some Pathfinder products have explored the idea of alien life in the past, and space ships and ray-guns have had their place in fantasy roleplaying games nearly from the beginning. This book, however, is devoted entirely to populating the stars with strange, terrible, and fascinating alien races of every sort, who can serve to breathe life into your game. Since most of these creatures will fit into the average fantasy dungeon at least as well as the froghemoth, the violet fungus, and the roper, even those who aren’t interested in the stars can still find plenty of use for the creatures in this tome.
From the insectoid, spindly-legged, and yet somehow graceful baaji (CR 12) known for impaling their victims on massive horns and treated as livestock by a variety of alien races, to the inscrutable zadar (CR 8), a race of grey-skinned humanoids with a wide variety of impressive alien technology, and mysterious, unknown goals, this book contains creatures of every CR from 1 to 20. The terrani (CR 1), a race of insectoid aliens driven into frenzy by hunger and lacking higher intelligence, are largely harmless when encountered individually, but if allowed to form into terrible terrani broods (CR 8) they can become a serious threat. The phase slime (CR 15) on the other hand is a bizarre phenomenon, whose body actually serves as a gateway to another dimension. All these creatures and many more can be found within this tome!