Monsters, monsters everywhere and... not a drop to drink?
That doesn't quite sound right. Though with the release of Bestiary 5 from Paizo for the Pathfinder RPG, you certainly can have monsters everywhere. I'm a firm believer that a DM cannot have too many resources at their disposal, so getting another plethora of monsters to throw at their players is a good thing (even if the players might not think so).
The book has over 300 different monsters contained within it. There's new angels, demons, and devils. There's new familiars, animal companions, and allies. There's new templates you can place on monsters to help fit them to just what your campaign needs. There's some newly-revised monster combat rules to help simplify everything. There's, of course, plenty of appendices to help you find the right monster at the right time for your game.
I hope your adventurers are well-supplied, as they're gonna need every sword and axe they can find to take on these baddies.