This pdf is 25 pages long, 1 page front cover, 1 page editorial, 1 page advertisement, 1 page SRD, 1 page back cover, leaving 20 pages of support for the druid. What do we get, you ask?
After an aptly-written, 3-page short story, we are introduced to new options for the druid, to be precise 10 animal companion alternate abilities that essentially replace other qualities the companions would get.
After these qualities, we are introduced to the first PrC, the Beast Master. The PrC gets medium BAB, good will-saves, full spellcasting, 4+Int skills per level and d8. The beast master allows a druid to forge a telepathic bond with her animal companion, enabling her to directly play the critter and enhancing its capabilities by offering a selection of 11 special tricks including hamstringing foes and causing bleeding attacks, culminating in a selection of 3 capstone abilities for the animal companion - nice to have a choice even at this high level. The class-write up comes with notes on their role in the world, lore-sections etc. and feels like a nice, valid option for druids.
The next class is the mystic shapeshifter, who gets a good BAB, medium fort and ref-saves, half spellcasting progression, 2+Int skills per level and d10. The mystic shapeshifter focuses on the wildshape ability of the druid, learning to keep keen senses like lowlight vision, the ability to speak etc. in all forms and, more importantly, to keep aspects of creatures when transforming into other foes: 10 aspects ranging from claws over fangs, wings and gills are provided to choose from and while from then on be featured by all the shifter's forms. The shifter's abilities culminate in the abilities to negate critical hits, sneak attacks etc. once per day and finally even include an armor's bonus and full protection when being shifted. While this capstone is ok, it felt a bit bland for a culmination of a PrC that had at 9th level the transformation to the shapeshifter subtype.
The final PrC of the pdf is the Totemic Spiritualist, who gets medium BAB, medium fort and will saves, full spellcasting progression, 2+Int skills per level and d8. The totemic spiritualist does not do something we haven't seen before, granting bonuses/abilities depending on the totem chosen. Bear, boar, eagle, fox and wolf are available, each offering 5 abilities over the course of the 10 levels. While there is nothing wrong with these, they also are nothing to truly write home about and some more far out totems would have been nice. They can, depending on their totem, modify their spells cast with some aspect of their totem, making for the most interesting abilities of this class, e.g. subtly casting spells or rerolling spell attacks. The capstone ability lets the spiritualist cast like this for a whole minute in addition to the regular, limited amount of times per day.
Editing and formatting are good, I only noticed some minor glitches. Layout adheres to the two-column standard and the pdf comes with a printer-friendly version. Artworks are nothing to write home about, which is ok at this price-point, though. The pdf comes with extensive bookmarks.
This is an interesting file to rate: On the one hand, we have a distinct lack of PrCs out there after the dread 3.5-glut and the PrCs herein are neither broken, nor badly designed. In fact, especially the beast master felt like a nice class to me that ought to work as intended in most campaigns. On the other hand, though, I felt that all 3 PrCs would have benefited from more options to choose from. PFRPG has moved away from the linear class-progressions and while the classes offer options, the don't necessarily offer as many options as I would have liked them to. More totems, perhaps a synergy with spirit warriors, more special animal tricks (though granted, animal companions benefit the most from this book) and a more exciting shaper-class would have been awesome. Remember those Wildshape-feats from 3.5? Updating and fixing them and putting them into a PrC would have made for a far more compelling and unique class than this shifter. Thus, once again, this is one of the books, that, while not doing anything particularly wrong, also fails to excel at its given field. Seeing the low price and the fact that animal companions get quite a bit of additional oomph from these pages, my final verdict will be 3.5 stars, rounded down to 3.