Master DM's Book: Monster List (Prime Plane)

The Monster List in the Master Set rules was divided into two parts: the Prime Plane (Actaeon to Sporacle) and Other Planes (Archon to Spider).

Prime Plane:

Illustration by Terry Dykstra, from the D&D Rules Cyclopedia (1991)

Actaeon - based on the story of Actaeon from Greek mythology

Adaptor - a race of plane-traveling shape-shifters

Athach - malformed, three-armed giants (name is from Scottish Gaelic folklore)

Beholder, Undead

Devilfish - based on the Ixitxachitl (from Blackmoor)

Dinosaur:

Dinosaur, Aquatic (Small, Large, Armored)

Dinosaur, Land Carnivore (Small, Large, Flying)

Dinosaur, Land Herbivore (Small, Medium, Large)

Dragon:

Dragon, (Crystal, Onyx, Jade, Sapphire, Ruby, Brown) - gemstone dragons*

 
*an article describing gemstone dragons appeared in The Dragon #37 (May, 1980)

Dragon, Pearl (The Moon Dragon), Ruler of all Chaotic Dragons

Dragon, Opal (The Sun Dragon), Ruler of all Neutral Dragons

Dragon, Diamond (The Star Dragon), Ruler of all Lawful Dragons

The Great Dragon, Ruler of All Dragonkind**

**see "The Mightiest of Dragons" in Dragon #158 (June, 1990)

Drake (Mandrake, Wooddrake, Colddrake, Elemental) - dragon-like shape-shifters

Faerie - invisible, aerial demi-humans

Giant (Mountain, Sea)

Hag (Black, Sea)

Hsiao - a race of strigiform, cleric-philosophers (name is from xiao)

Human (Headsman/Thug, Mystic) - based on the Assassin, Monk from Blackmoor

Lich - from Greyhawk

Lycanthrope (Werebat, Werefox,* Wereseal,** Other)

*from B4 "The Lost City"

**based on the Selkie (from the AD&D 1e Monster Manual II)

Mek - huge, metallic, insect-like creations

Metamorph - a race of humanoid shape-shifters

Illustration by Jeff Easley, from the Master DMs book (1985)

Nekrozon - based on the Catoblepas (from The Strategic Review #7)

Nightshade (Nightcrawler, Nightwalker, Nightwing)

Nuckalavee - based on the Nuckelavee of Orcadian folklore

Ooze, Lava - a magma ooze

Revener - see this Facebook post:

I was developing a variety of beings for the Spheres (Matter Energy Time Thought), and the 5(6) senses are often ignored or irrelevant in most games.  That said, I'm sure some culture produced something similar.  (It often goes unused by DMs because it's not easy to run, and isn't cool-deadly-combat stuff; more for roleplaying.

Frank Mentzer (January 27, 2020)

Illustration by Jeff Easley, from the Master DMs book (1985)

Sasquatch - based on the Bigfoot of North American legend

Slug, Giant - from Greyhawk

Sphinx - from the AD&D 1e Monster Manual

Sporacle - a Beholder-like creature