The first supplement of Raging Swan Press' new line "100% Crunch" is 38 pages long, 1 page front cover, 2 pages editorial, 1 page ToC/foreword, 1 page advertisement, 1 page advice on how to read statblocks for novice DMs, 1 page SRD and 1 page back cover, leaving us with a total of 30 pages of content for this installment, so let's check this out!
We kick off this pdf with a table of skeletons by CR before we delve into a one-page step-by-step guideline on how to create skeletons with damage, XP, natural armor bonus etc. all neatly calculated for your easy use - with this, creating your own bony undead will probably take considerable less time - which you can use to ponder new options, like the 8 simple skeleton variants, which provide easy on the fly modification for your skeletons via the most basic of simple templates, ranging from under-equipped (CR -1) skeletons over those oozing acidic sludge (CR 1) to skeletons bearing a curse and even mudra skeletons, i.e. many-armed ones - 4 arms equaling CR 1, while 6 arms mean CR 2. Two more complex, classic variants of skeletons are also covered: The Bloody Skeleton, which regenerates unless destroyed by positive energy and the burning skeleton, which comes with a fiery aura and additional fire damage.
The next 4 pages will be a godsend for any DM looking for some base-creatures: Organized by CR of the final skeleton creature (including racial HD-information) and Bestiary in which they're found, they also provide information on whether e.g. such a creature would be aquatic.
Well, after that, though, we're off to CRUNCH. A lot of it. Organized by CR, we get a vast array of different pregenerated skeletons for your perusal that range from dire rats and drow (at CR 1/3) over Bloody Goblin Skeletons, Grave Chill Skeletons (essentially the cold brothers of their burning brethren), dolphin skeletons, exploding 4-armed ogre skeletons to those of elephants, elasmosauruses, siyokoy, ghaeles, giants, sea serpents and even dragons and a statblock for the remains of a Tyrannosaurus Rex. And if you don't realize how cool a skeleton of a Tyrannosaurus is, you have to start reading Dresden Files...
If I haven't miscounted, you'll find a total of 99 statblocks spanning CRs from 1/3 to 8 in this book - quite an array!
Editing and formatting are as top-notch as I've come to expect from Raging Swan Press. Layout adheres to their elegant no-frills, two-column standard and the pdf comes with extensive, nested bookmarks, while also providing 2 basic versions of the pdf: One optimized to be printed and one for screen-use. Much like the "So what's..."-series, this pdf is definitely a godsend for DMs in that it takes a lot of unpleasant work off one's shoulders. by providing the easy step-by-step process, lists for the bestiaries and a vast array of sample statblocks, the pdf ensures its usability almost from the get-go and can be definitely considered a time-saver par excellence when you're currently creating some skeletal minions for necromancer, priests of Orcus or similar villains. The simple mini-templates/variants included are also nice, though I would have loved to see at least one that hasn't been done before - multiplying, bloody and burning skeletons are nice, yeah, but could we perchance have a some more customization tools?
Bone-splinter breath-weapons? Hollow bones filled with alchemical essences? Something like that? That being said, this is nagging at a high level. While not particularly cheap, the maximum usability and concise presentation of this book will, I am sure of that, ensure its value for almost any DM out there apart from those who so routinely modify monsters that they can apply templates on the fly. Due to the aforementioned lack of a truly new piece of content, though, I can't really rate this at the absolute peak - My final verdict will thus be 4.5 stars, rounded down to 4 stars for the purpose of this platform. I hope to see more variants/modifications to go with the excellent statblocks provided by the series in future releases.