The Practical Guide to Monsters has a few monsters that don’t have Microlite20 versions. Ormyrrs stick out to me more than the others. For reference: Thri-kreen, Yuan-ti, werebear, wereboar, ghost, and lich do not have M20-style stat blocks that I have found. Some of those have enough substitutes you can reskin (lycanthropes and generic undead), while “lich” can be applied as a template. But I like these slug-looking characters that clearly have no relation whatsoever to Hutts. In fact, the D&D Fifth Edition doesn’t have them, either.
Orymyrrs have enormous grublike bodies that possess powerful arms, a mouthful of extremely sharp teeth, and a surprisingly intelligent brain. They aren’t particularly aggressive, tending to keep to themselves.
While (or perhaps because) these creatures have no talent for casting spells, they find magic absolutely irresistible. They will lie, cheat, and steal to obtain a scroll, spellbook, or other magical object, and can be mesmerized by a skillful display of magic powers.
The book also notes that they tend to live in a solitary state or in small tribes of no more than one dozen. I would use the following stat block. DMs may want to adjust the to-hit numbers (especially slam). They should also target magic users of whatever flavor first.
Ormyrr: HD 7d8+7 (43 hp), AC 15, Slam +6 (1d4+1), spear +8 (1d6+6), constrict (2d6)
I recently got a copy of A Practical Guide to Monsters. An in-universe reference volume for apprentice wizards, it lists 53 different monsters by my count. Each of them has a bit of fiction, a fact box (e.g. height, weight, habitat, diet, attack methods, etc.), and an artistic representation. If you think this sounds like a Monster Manual, then you’ve got the idea, but the book includes no game statistics. In effect, you can think of the guide as a monster manual for kids. Some of the monsters even have associated maps and marginalia.
The illustrations bring out the ideas behind each monster without scaring small children. A few of them include a child-like goblin running away or otherwise engaged in some activity. This gives kids a way to imagine themselves interacting with the monster but in a reasonably survivable way. Several intermediate sections list weapons, armor, and equipment that an adventurer might need. My kids and I have had a nice time looking through it and talking about what it might feel like to run into some of the monsters.
I don’t want to give the idea that the guide only works as a children’s book. The free Dungeon Master’s Basic Guide lists statistics for a little under half of the listed monsters, and the Monster Manual for 5e includes almost 90% of them. Exceptions include the Yrthak, Ormyrr, and Athach, among others. The Microlite20 expanded monster list includes about the same number. A GM could easily convert the exceptions from other editions.
So in addition to the coffee table aspect, this book works well as a way to illustrate monsters to players. A game with children or using a retroclone would particularly benefit. Wizards of the Coast first published the book in 2007, so lots of stores carry inexpensive copies. They published a whole series of Practical Guides (“wizards”, “dragons”, etc.) and I look forward to getting a few more for my home library.