There were ultimately three monster books released for the Planescape setting, the Planescape Monstrous Compendiums I-III. They eschew the product numbering of the rest of the Monstrous Compendium line, which was a mess anyway. The first printing of the AD&D 2E Monstrous Manual was a big binder with loose-leaf monster entries, running off the idea that additional monster supplements could just be slipped in and you’d have all your monsters in the same place. While I like the idea, they’d have needed something in place to address the issue of new monsters that fall alphabetically between two creatures that are on different sides of the same sheet. Anyway, by the time this book rolled around, that concept was dead and buried, and thus in 1994 we got this lavishly illustrated 128-page book and its sequels. Well, by the time this book rolled around the second time.
A lot of Planescape Monstrous Compendium Volume 1 — or PSMC1 — is actually recycled content from 1991’s MC8 Monstrous Compendium Outer Planes Appendix. And when I say “a lot”, I mean “nearly all”. There’s a convenient Wikipedia page that lists the critters and where they’re originally from (while it’s generally bad form to use Wikipedia as a source, but I did check, and at least now in late March of 2020 it was valid). MC8 has 91 monsters, while PSMC1 has 105. By a quick count, 71 of these were carried over. Of the remaining 20, most resurfaced in Planescape Monstrous Compendium Appendix II and Planes of Law (notably the archons). Only the air sentinel, the celestial lammasu, and the adamantite dragon didn’t make further appearances. The air sentinel is basically an off-brand djinn native to Bytopia (or the Twin Paradises as it’s still known at the time), and the other two are what it says on the tin. The adamantite dragon is also native to the Twin Paradises. Its breath weapons are the traditional cone of flame, and a time stop effect. Planescape didn’t really do dragons, which is probably why it made no further appearances.
All this makes PSMC1 a dissonant book. While the art was all redone by Tony DiTerlizzi and the layout is the Planescape we know and love, complete with in-character blow-up quotations, a lot of the text was not given the proper attention. While it’s by no means just copypaste, and some entries are lavishly expanded from the original, the fact remains that MC8’s writer J. Paul LaFountain was not a particularly good prosaist. The text is janky, which is thrown into sharper relief when it sits alongside material written specifically for this book.
However, PSMC1 is a vital book. It gathers together most of the major critters of the setting with the exception of modrons and some of the good-aligned outsiders. It’s got the main lineups of baatezu, tanar’ri, and yugoloths. There’s the marut, which D&D 3E later ran with and used as a springing board for the inevitables. There’s the random monster generator that is the hordling, there’s tieflings, shadow fiends, night hags, and the animal lords of Beastlands. We’re introduced to the combatants of the Blood War and the whole larva ecosystem/economy that the Lower Planes have got going on.
Most of the art is good, though a couple of the fiends only have very closely framed mugshots that don’t really tell much about how they look besides ugly, and it took me until the 3E-era Wayne Reynolds illustration of the ultroloth to figure out what it looks like.
Possibly my favourite thing about this book are the mephits. They’re basically elemental imps; small, winged humanoids with breath weapons and bad attitudes. The core of the entry is boosted off MC14 Fiend Folio Appendix, but that one has six mephits whereas this book has sixteen, one for each elemental, paraelemental, and quasielemental plane. They’re characterised by weakness as combatants and being an amusing collection of unwanted personality traits, but what makes them really shine is the concept of mephit messages. They are used as messengers by more powerful creatures, but the mephit itself is the message, and the type of mephit sent. A radiant mephit offers truce, a salt mephit declares open warfare, and so on. It’s like the language of flowers, if the flower was also an asshole to your pets, smelled bad, and tried to cadge cigarettes off you.
Next up is Planes of Chaos, and I’ll see if I can’t draw something more interesting out of that.