From the back cover:
Thought you'd seen it all when you met the neogi? Threw up your hands in horror at the sight of space barnacles? Well... get ready for the giant space hamsters, the symbionts, and lots of other wild and weird Spelljammer campaign monsters!
In this product are some of the most fantastic creatures ever seen (or not seen, as the case may be), in wildspace or out of it. Yes, Virginia, there really are giant space hamsters lurking in these pages, as well as whole new races ready for the DM to launch into a Spelljammer campaign. Once again, there are 64 pages of new beasties for your playing enjoyment, 5-hole punched and ready for insertion in your Monstrous Compendium binder. Plus, the great full color divider pages with identification tabs make it easier to organize your critters.
Spelljammer campaigns will never be the same again...