I must admit that I'm of two minds about the duplication of some monsters between chapters IX (Mythos Bestiary) and X (Expanded Mythos Bestiary).
Some have only minor differences (Bholes), while others are two different monsters types (Wendigo) or have other differences. Was this a question of re-developing the source material in order to better suit the original vision? Maybe that explains chapter IX.
Was this sort-of duplication necessary? Maybe. IIRC, the Mythos-related monsters have in the past been scattered around in various Bestiaries, AP instalments, etc, and those are the ones that have now been collected in chapter X.
One thing is for sure: adventurers will now have a harder time identifying the creatures. "It looks a bit like a wendigo, but I'm not sure if it's the aberration or the outsider version. Shall we try a Banishment and see if it works?"
Or be a really nasty GM, and combine the worst aspects of both versions. I'm sure that the high-level party (L 15) can take it! :)
If I remember right, one version is a reprinting of mythos monsters from other bestiaries and books - collecting them all in this single, theme-focused book for ease of reference - while the second set is an original/altered take on the creatures. Certainly seems like it'll keep people on their toes. XD
|James Jacobs Creative Director|
The point of the "Expanded Bestiary" was to gather up all of the OGL monster stats for these critters as they appeared in Paizo Bestiaries with no re-design; putting them all in one place for folks who prefer those stats.
The content of Chapter IX is the brand new design that we did for the book, providing new takes on a lot of the monsters with Sandy Petersen's feedback and inspiration from him to incorporate his ideas.
Use the ones you like better, or switch back and forth to keep your players guessing.