In the interest of full disclosure I will state up front that I received this product free.
Familiars are a prime candidate for coverage by third-party d20 publishers, given that less than a dozen animals are available in the core rules, without much in the way of options for augmenting them. Over the past year there have been several publishers to step into this void, the one at hand being Dark Quest with Dweomercraft: Familiars. The version at hand is in PDF format, released under the EN Publishing banner.
This PDF runs 124 pages and weighs in at about two-and-a-quarter megs in size in a zip. There's a lengthy Section 15 at the end with many third-party sources cited. Dweomercraft: Familiars was evidently an ensemble effort with Steve Creech, Michael Hammes, Neal Levin and David Woodrum all sharing the writing credit, and five others credited for additional writing. Art is handled by Ceredwyn - I liked a few pieces such as the chapter headings and the mechanical owl on p. 47, but not others like the inhabitants of pages 74 and 117, which had personality but were just too sketchy and flat for my taste. Only the opening pages have borders, and the table of contents is hyperlinked for easy hopping.
I caught a few errors - "it's" when "its" should have used on p. 103, and the 3.0 skills of Alchemy and Scry appeared in the Magebond's skill list even though this is a 3.5 product. Definitely most troublesome for me are some elusive entries for our feathered friends that have left me very confused: duck, ostrich, swan and turkey are alluded to in Tables 6-1 and 10-2, but I can't find stat information for them anywhere in the product. The mocking bird and vulture are listed in Table 6-1, but I found no actual stat info for them either. The goose and hummingbird from Table 10-2 also seem to have flown the coop.
Much of the opening pages' content is given over to flavour text. There's quite a bit of flavour text running through the book and overall it's pretty good, fortunately. In Chapter One, The Relationship Between Master and Familiar, familiar preferences among the PC races are discussed, though dwarves appear to be missing. Other races such as drow, kobolds, orcs and so on are covered as well. The chapter goes further by outlining familiar traits - mostly undesirable traits like being stubborn, envious and so on. There's a clear effort in this chapter to attempt to get players thinking about their familiars as unique beings with personality, instead of a bucket of stats carrying a bonus to the master around. There are even minor curses as an option to impose upon masters who intentionally mistreat their familiar.
Chapter Two: New Origins quantifies new ways for masters to find their familiar. Spells requiring expensive material components or feats are suggested for those who want a more powerful familiar than can be attained at 1st level. Suggestions for origins of the familiar include being an essence of the wizard's mind brought to life, a former construct given the spark of life, or the reincarnation of a wizard.
Now it gets good. Chapters Three through Twelve are the real calling card of the book and more or less the same format, so I'll just make general observations here. Each chapter begins with some flavour text and then devotes a page or so to reasons you would and wouldn't want a familiar of this type, what kind of person would take such a familiar, and what kind of care this kind of familiar needs (more roleplaying considerations). Any relevant spells and rituals you'll need to get the higher-powered familiars are provided, and in a few cases there are diseases that familiars of that type are vulnerable to. When a creature's stats are already available in the SRD its benefit is simply listed in the appropriate table. When new familiars are introduced they're statted out in full monster blocks complete with with CRs, climate/terrain, the whole deal. Some creatures are what you'd expect to see and others are quite creative. The chapters are:
Chapter Three: Other Planar Creatures. Familiars with origins from other planes, and elemental familiars as well. Hellhounds and mephits are among the recognizable creatures here, while new creatures include the Phenix (a tiny bird with the fire subtype) and the Prismatic Archon for righteous characters who are willing to save up for a CR 5 familiar. The basic four elemental types are here, as are the composite subtypes like dust, ooze, lava, etc. There are yet more elements on top of that; if you ever wanted a rust or vapor elemental, here's your ticket.
Chapter Four: Undead Familiars. A necromancer with an undead familiar makes for a classic evil NPC, but its appropriateness for a PC in a typical campaign is more questionable. That could be why this chapter is fairly short with just a few new familiars like the flying skull. There are a couple of warnings on how a PC's undead familiar could unbalance the game in a campaign.
Chapter Five: Constructs. Animated constructs are among the most powerful familiars you'll find, and the magic required to obtain them is hefty, even for a little one. Not only are constructs low-maintenance and packed with immunities, but these construct familiars can be very intelligent as well. The expected golems and animated objects are here, together with a couple of new golem materials (amber and straw) and a couple of completely new concepts like the Living Rune (basically a floating, living spell).
Chapter Six: Avian And Other Flying Familiars. With the more fantastical familiars out of the way, the next few chapters are of the more mundane "animal kingdom" variety. Fine by me, I always like having more animals for characters to polymorph into, or starting points to create enlarged or monstrous templated versions of critters from. Here in Chapter Six you'll find your blue jay, kiwi, seagull and so on. Starting with this chapter, there are a list of upgrades the master can obtain for a familiar of this type by spending XP for enhancements such as increased movement speed, a spot bonus, extra attack bonus, and so on.
Chapter Seven: Reptiles. There's a generic "lizard" presented to encompass a wide variety of standard lizards, but among new specific reptiles here are chameleon, gila monster, komodo dragon and a couple of turtles.
Chapter Eight: Rodents. Here you'll find the chipmunk, ferret, mouse, shrew, gray squirrel and the like. If you want people to leave you alone you could get a skunk familiar, and a mole would make a cool familiar for a gnome.
Chapter Nine: Vermin. This is a brief chapter as vermin are another kind of familiar that are not likely to be too popular. There are only a few new animals like cockroach, crab and snail.
Chapter Ten: Exceptional Beasts. Here's a large catch-all for animals that don't fit into any of the previous four animal chapters. So there's a badger, chicken, fox, penguin, pot-bellied pig, rabbit, seal, and much, much more. I was glad to see the chicken made it in; there's actually a bit of historical record from centuries ago noting the claim of dark-coloured chickens being familiars for witches. Canadian mages could have a beaver, while Australians may opt for the koala bear. The tasmanian devil is here too, with a suggested geography-neutral name, the rage devil. At the end of the chapter is the horrible ritual of sacrificing a familiar to raise a blighted familiar, which kills plants and spreads disease.
Chapter Eleven: Monstrous Humanoid. This one gets further "out there" with sentient creatures like blink dog and goblin. Earlier editions of D&D did allow pseudodragons and brownies as familiars, so the pseudodragon is here, as are the grig and pixie. A seneschal is a template that allows any humanoid or monstrous humanoid to be bound to a master, although the flavour text strongly signals that it's not considered something that good folk do.
Chapter Twelve: Oozes. A very short chapter which pretty much concedes that ooze is a very odd choice of familiar, but the requirements to get one aren't steep. There are two new tiny oozes, the goozaling and taffinymph. This is the last chapter covering specific familiars.
Chapter Thirteen: Equipping The Master And Familiar looks at familiar equipment, starting with basic feed. Familiars need to eat too, after all. It's easy to just lump it in with a general upkeep payment but in a roleplay-intensive campaign, it's reasonable that masters should at least make a token effort now and then to show they're looking after the familiar's needs. Following that are some special items such as the sizzlerock, a warm rock that will ensure the comfort of familiars who want or need warm places to curl up to while travelling. A few magical items are also listed, from the mundane but useful Bowl of Staple Rations to the flashier Collar of Flying. Three cursed items complete this chapter.
Chapter Fourteen: Making Familiars Tougher explores the option of giving familiars character classes, and abilities that augment their power. The only prestige class in the whole book is here; the Magebond is a character who has a very strong bond with her familiar allowing them to share magical energies. There are 11 familiar-themed spells, and there's a little bit of attention to the notion of familiars being used for core classes beyond just the sorcerer and wizard. The product ends with prestige familiar options, in which a master can sacrifice XP to let a familiar gain a certain feat or other benefit, such as growing wings.
Dweomercraft: Familiars is a good product for anyone looking to bring some life to the often-neglected field of familiars. Newer gamers, or gamers who just haven't given much thought to their familiar, could benefit from the ideas in the first couple chapters of the book. I wasn't all that interested in those parts myself; the prime attraction for me was the new familiars and augmentations for familiars, which makes up most of the product. The obvious comparison for me is to Mongoose's Encyclopedia Arcane: Familiars since I also have that one. While Dweomercraft: Familiars is twice as long and more comprehensive I'm still glad to have both, as the Mongoose book has different ideas about similar things and has more support for powerful SRD monsters like unicorns and dragons, plus a little more in the feats/prestige classes vein. So to me, Dweomercraft:Familiars isn't quite the complete and final word on the subject. But it's good. Those who are interested in brand-new familiars or familiar augmentations should be quite happy indeed with Dweomercraft: Familiars.