Myconid (AC 6 HD 1-6 Att 1, weapon or spore Save F1-6 Moral 8)
Vegepygmy (AC 8 immune to piercing weapons HD 2 Att 1, weapon Save F2 Moral 8)
Perhaps a few others. Yellow/russet mold and the like, which will largely be unchanged from B/X.
Squill (AC 5 HD 4 Att 1, bite 1d10 Save F4 Moral 8)
Squills are semi-Intelligent squirrels about the size of a small cow. They have large forepaws and ringed tails, and communicate with a loose chatters. They vary widely in color and will sometimes paint their fur in decorative circular patterns. They are highly territorial even though they are primarily arboreal, and are difficult to trade or communicate with. Squills will most often attack in small war parties and nibble off the feet of any intruders rather than outright kill them.
- Acorn totems – Squills will place large amounts of dried acorns in hollowed totems, reaching 40 feet or more. These totems will have animal carvings and are usually brightly painted. The totems will appear in erratic locations in the wilderness surrounding the Great Rot communities.
Eloewn (AC 7 HD 1 Att 1, weapon Save F1 Moral 8)
This is a race of intelligent leafy men. They appear as man-sized walking-sticks with autumn leafy filaments between their appendages. They are usually peacefully and quietly go about their unfathomable business in the remaining warm compost heaps in the world. With their ecology slowly dying the Eloewn are becoming more desperate and aggressive. Leadership figures grow cones which are attached them and procreate the species with the seeds inside. The Eloewn often are at odd with the Squill, whom find the cones of the Eloewn irresistible.
(This a nod to the Elowyn in Starflight)
Humgrois (AC 4 HD 3 Att 2, bash 1d8/1d8 Save F3 Moral 10)
Humgrois are mottle-skinned humanoids which have large distended bellies that perpetually drag on the ground in front of them. They have massive forearms and lope on all fours when moving with speed. Unclothed and unwashed, they seem about as intelligent as any ape creature. They may seem docile at first, even offering travelers a loose piece of fruit or hunk of raw meat. However they will just as casually brain any intruders with no warning.
Twilight Beast (as creature)
These are creatures born from the second year of the Great Rot. They are similar to creatures of their original heritage but are often desiccated, have a musty smell, mottle autumn colored skin, and speckled hair. Stat-wise they are identical to their normal peers but have different behaviors that could be described as eccentric.
Crawlurk (AC 2 HD 5 Att 2, claws 1d10+1/1d10+1 Save F5 Moral 11)
These fungi-encrusted crawdads can grow up to twenty feet in length and dwell in mulchy damp areas. Crawlurks prefer to cover themselves with damp leaves and ambush unlucky prey that walks too close.
Mulid Worm (AC 9 HD 1 Att 1, bite 1d8+1 Save F1 Moral 12)
These large flat worms have a segmented jaw that can latch onto fleshy prey. They prefer to scrape off anything they can digest and are usually content with a hunk of flesh rather than outright killing any prey. They dwell in rotting trees in small numbers but will unfortunately layer themselves in large colonies in large compost heaps.
The Folding Deep (AC 9 HD 5 Att 2d12, save vs stone for half Save F5 Moral 12)
This large sheet of lichen carpet will cake itself onto a rocky perch and fold itself upon anything that stands upon it. It is typically a frosty green and about one inch thick, and can cover up too twenty square feet. It will quickly seep any water and salt out of the victim causing an immense amount of pain in the process.
Polypods (AC 10 HD 1hp Att none Save F1 Moral 12)
These are polypores that attach themselves to anyone or anything venturing in the remaining areas perpetuated by the Great Rot. They can be scrapped off easily but have the propensity to return over time. If allowed to grow on flesh they are itchy, but eatable. They are otherwise harmless.