In 2008, Sham's Grog 'n Blog featured a series called "D&D Cover to Cover" that gave a thorough reading of the 1974 Dungeons & Dragons rules. In it, he covered the original Monsters & Treasure volume, beginning with this post. In it, he broke down the monsters into the following categories.
The Monster Categories:I think this is a good look at the basic categories that a monster book should cover. "Bad Guys" is our classic list of meat and potatoes enemies, which looking at bestiaries published since is one of the harder ones to expand upon - consider that all we've seen added to that list of humanoids that has stood the test of time is the bugbear, and some oddball ones like the lizardman. It's a challenge to come up with something for this that isn't just a re-skinned version of what's already there. "Dead Guys" is a little bit more expansive, but these still represent the main mechanics of undead: the level drain, aging, mummy rot and so on.
Bad Guys: Men, Kobolds, Goblins, Orcs, Hobgoblins, Gnolls, Ogres, Trolls, Giants.
Dead Guys: Skeletons, Zombies, Ghouls, Wights, Wraiths, Mummies, Spectres, Vampires.
Save or Stoned Guys: Cockatrices, Basilisks, Medusae, Gorgons.
Monsters of Myth: Manticoras, Hydras, Chimeras, Wyverns, Dragons, Gargoyles, Lycanthropes, Purple Worms, Sea Monsters, Minotaurs.
Fairy Tale Miscellany: Centaurs, Unicorns, Nixies, Pixies, Dryads, Gnomes, Dwarves, Elves, Treants, Pegasi, Hippogriffs, Rocs, Griffons.
The Otherworldly: Invisible Stalkers, Elementals, Djinn, Efreet.
Icky-Stuff: Ochre Jelly, Black Pudding, Green Slime, Gray Ooze, Yellow Mold.
Monsters Mundane: Horses, Mules, Small Insects and Animals, Large Insects and Animals.
As Sham pointed out way back in the day, "Save or Stoned" is really a part of Monsters of Myth. And the bestiary for OSRIC of that name does include more, but this category really switched to being a wide array of ugly things and not a focused monster grouping. It's also telling because Sham's copy of M&T was from the 6th printing and missed the balrog, whose
The fairy tale monsters are a class that is easy to overlook as monsters. One of my ideas for the dungeon level I've been working on lately includes a rather unique use of gnomes, since I think "non-evil" opponents are under-utilized. I would really like to see some scenarios out there that take advantage of fairy tale creatures which are "different" rather than evil per se.
I would say that "The Otherworldly" has been one of the most expansive historically; by Monster Manual II there was a significant catalog of demons, devils, angels, and other creatures from the various planes. It's a rich field and often interwoven with mythology. This sort of monster is evidently the focus, for instance, of the Teratic Tome that I've been made aware of recently by G+, and is a broadly popular opponent for later stages of the game. I like them but I'm not sure that it's ripe for new exploration.
The "Icky Stuff," which Sham later recognizes as being labeled the "Clean-Up Crew" (see this post), is another that gets little love. The gelatinous cube got added, but really very little since then; yet this is a rich area that can really make a dungeon dangerous beyond the plain old monsters, and create a very full array of "don't touch" sort of things. One inspired addition is the tunnel prawn, which was featured in Monsters of Myth, and provides a simple and fairly obvious source of nutrition for many of a dungeon's denizens.
Finally the mundane monsters are, on the whole, fairly well used - but they don't really need detailing in a new volume. I would be sorely disappointed if all I got in a book was new rules for giant rats and so forth, rather than the "real" monsters I was looking for. Although, as this RPGnet thread showed, the average housecat in D&D became a stealthy kitty ninja of death lurking for first-level PCs. (Or rather, that's what you get when you try statting out everything in existence.)
So for me, a solid new monster tome would try to add a few new entries to the "Bad Guys" without too much duplication. But the focus would be on the Monstrous, the Fairy Tale, the Otherworldly and the Cleanup Crew - possibly even featuring a division into those parts instead of the Monster Manual style of simple alphabetical listing. It always seems to me that just listing things alphabetically is a way to make sure that some inspired bits get missed because you're skimming past the letter "k" or some such.
Next post, I'll talk a bit about creating an "inclusive" format for a bestiary.