This current Kickstarter has a handful of them:
http://www.enworld.org/forum/conten...ckstarter-for-5e-Pathfinder-WOIN#.WDhReiOcZTY
Are there specific creatures you need? On Dungeon Master's Guild there are a Lovecraftian Bestiary and a Volume 2 of the same; they cover gugs, colours out of space, elder things, Mi-Go, rat things, and a couple other critters. The PDFs are two bucks each and have decent illustrations.