Wizzzargh did it first, and they have more in-depth takes on the original monster manual entries that I won't get into. Instead I'm just going to stat/flavor these somewhat quickly as an exercise and attempt to get this blog running again. I'll be linking their posts as I go through and would recommend checking out Wizzzargh's posts and cool art.
All of these are based off of Centras, my ongoing setting containing Runeforest/Shell and Stone and the like.
So without further ado:
Aerial Servant : Elementals come in all shapes and forms and you can hire them with a contract in the right language. All services are tit-for-tat. They are sometimes used as assassins by unscrupulous sorts, but
1) Their kills are fairly obvious, since they tend to just bludgeon someone to death (they hate getting wet and know that people have blood)
2) They are very gossipy, and elemental contracts require an exchange of True Names.
Thus mages with Law Enforcement can usually consult elementals themselves to quickly discover the name of a killer. This has lead to some interesting cases of counterplay and lengthy investigations nonetheless.
Ankheg: Insects of all sort live under the earth and sometimes come to the surface during the Spring and Summer seasons. Because the taxonomy of insects is so diverse compared to surface-dwelling humanoids (who barely survived the Great Fires), it's rare for anyone except experts to know their names. Instead, contracts get put out for "giant bug what' ate me' crops!" and some sword-swinger will come along and try to deal with it without dieing.
Ant (Giant): Ants are used as mounts by Antfolk, but they're pretty rare (the big ones at least). Sometimes a swarm of ants will gain sentience and take the form of a Giant Ant from latent Runeforest magics.
Apes (Gorilla/Carnivorous) : Regular gorillas aren't around anymore, they were granted intelligence and wings or claws by a dead god. Pushed to the brink of extinction by the Godclaws forces. If they show up on a table, it'd be a feral tigorilla or derhii driven mad without it's wings.
Axe Beak: A strange Runeforest creature. They can eat magic weapons to bestow it's latent enchantment on their beak. Intelligent weapons consumed can easily inflict their Ego upon their beastlike "wielder", leading to some frightening encounters with highly-intelligent and tactical minds inside a murderous giant bird. They also come in titanic varieties and are sometimes used as giant mounts.
Baboon: These are just a type of small goblin that wear funny masks
Badger: Some are nice and some are very mean but they probably won't pose much of a threat. Unless they are enlarged by magic. Then you should probably run.
Baluchitherium: Nope
Barracuda: It's a fish with teeth
Basilisk: These were a bigger deal in the Age of Heroes, nowadays they are mostly a threat in wyld places like the Runeforest. They are symbiotic with Silenced Flesh to Stone spellwisps, which is the source of their petrification abilities. Most variants are snake-like except for some found in coastal regions which resemble large iguanas.
Bears: Common Runeforest threat. Rune-variants tend towards magical claws. One common subtype called "Skull Bears" are large and black with a white, skull-like pattern on their chest. Eating Skull Bear meat is known to bring about a dreaded "curse" (actually just really bad diarrhea, a common piece of apothecary advice is that if you have to eat any meat from a Skull beast you should cook it with an herb named after a Saint)
Giant Beavers: A rare Runeforest encounter. If you're lucky enough to find and parlay with some you could probably get a great deal on scrap lumber or dam construction costs.
Many summers ago, during a previous Runeforest incursion, a rune-pelted giant Beaver began constructing great castles in the woods. The Fae and Adventurers marveled at first..until the Beaver named itself "Kastor Khan", taught other beavers to carve spears from the Rune Trees, and began a war campaign that claimed several forts belonging to the Court of Summer. Kastor Khan was pushed back at great cost....but some say he lives on, sharpening the spears of his brethren as he plots his revenge against Man and Fae.
Beetles: Beetlefolk and their Beetle Kin are hearty, unbothered creatures. They take the Summer Insect Pilgrimage quite seriously and have been known to simply wander through great battles, seemingly unaware or uncaring of their surroundings. Some take positions in the church of the insect-god Ka'Thon where they act as martial masters, showing students how to better use their shields and armor as an extension of their bodies.
Beholder: Remnants of the nearly-extinct deep sea demons from Stone-And-Shell. Basically unheard of in the Runeforest, though the Rune Logicians of Polis would really like to collect one for better component study.
Black Pudding: Mutated Ink Elementals who's stains just so happen to be a bit more permanent.
Blink Dogs: Are not traditionally sentient unless they are a blessed Cerberi. They are bred but not sold by the Hound Dealer's Guild of Polis, instead kept exclusively as companions for high-ranking members or friends of the Guild. Anyone can get a Basset Hound of Tindalos though, but those can only jump out of right angles (Available with Purchase!)
Boars: Another Common Runeforest threat, and similar to bears, rune-variants tend towards magical tusks. Unlike bears though, Boar meat actually tastes good.
Brain Mole: Nope
"Buffalo" (actually Bisons/Yaks): So most gods like the smell of cows, and also cows are delicious. So humans domesticated them. But apparently The Wyld took offense to all this for some reason, and thus we have Bisons, which are extra tasty cows hiding behind a ton of muscle and aggression. Rune-Bison tend not towards magical horns but instead magical hooves, severe variations in size, and hive-minded tendencies. Stampedes are incredibly disastrous but thankfully rare. Yaks are an offshoot of bison and cow. They are sentient, hearty pack animals that gods and similar entities like to make pacts with, bestowing the yaks with the ability to cast spells.
Brownies: A type of mischievous and occasionally helpful Fae fairy, able to remain invisible. Their helpfulness and tricks depend on their Court association, and they are a common boon or bane for those favored or unfavored by a particular Court. They are also incredibly shy and hate being discovered outright.
- Autumn Brownies: Aid by alerting you to pickpockets, thieves, and other ambushes. Trick by spying for your enemies, "stealing" coins and other treasures (really just burying them or hiding them somewhere else in your campsite), and tying knots in all your rope.
- Winter Brownies: Aid by tending your fires and patching up holes in your clothes. Trick by putting out fires and biting holes in your clothes and sleeping bag.
- Spring Brownies: Aid by helping prepare and cook your meals and cleaning your cooking and eating utensils. Trick by spoiling your food and ingredients.
- Summer Brownies: Aid by polishing, sharpening, and helping care for your weapons and armor. Trick by dulling your blades, misplacing your ammunition, and dirtying your armor.
For a "Bugbear" result on an encounter table, it's just a large martially competent goblin wearing an animal pelt.
Bulette: Sandsharks have been reported in the Southern Deserts and the occasional Island, but aren't particularly common. The Runeforest does occasionally make unique monsters though, which could certainly include a burying-shark monster with bulette stats. They might also just be a type of large, undiscovered bug.