Beetle Horde aka Gassy from the Jhora Plains
Beetles that carpet the radius around the pillar of Equinos. They are not entirely organic in construct and theorized to be magical in nature. Attempts to use divination and animal ken on the creatures diminish over time. Strangely, revocation causes them to explode when revocation should normally not have that effect on living things. This seems to imply they are creatures of pure quasith.
Brenthian Cave Ants
Their are colonies of giant, carnivorous ants in the Brenthian underground tunnels. Some tell tale signs of their presence are: small scatterings of falling dusts from their tunneling, roughly tunneled holes that don't look Husker in design, and the lingering smell of rotted meat if they are feasting on a fresh kill. Their danger hasn't been assessed since they've not been engaged yet.
Brenthian Slimes
These are slow moving, gelatinous creatures with low, insect like intelligence. They feed off of minerals and hard substances that they consume by corrosion. They can be made to grow with Chracio pit sand, multiplying greatly in size. It's unknown if regular sand has the same effect.
Brenthian Tunnel Bats
The bats in the Brenthian underground tunnels are one of a few known beasts that inhabit the environment. So long as you can see in the dark, they are usually easily spotted hanging upside down from cavern roofs. Their danger hasn't been assessed since they've not been engaged yet.
Sentient, intelligent scarab/centaur like creatures who command insect hives telepathically and can attune to pillars.
Condors
Condors are massive vulture like birds that inhabit the mountainous regions near Serosan. They are hunted by the Serosan's griffin riders because their feathers, meat, and eggs are all valuable commodities. Hunting condors can be a dangerous endeavor given their massive size and protectiveness over their unhatched young. They are also resistant to electricity.
There is also a pack of giant, sentient Condors attuned to a hidden, mountaintop pillar, Paraxos. These condors have demonstrated various magical abilities like telepathy and electric evocation.
Direwolves
These large, human sized wolves with sharp fangs, tough hide and bone, and highly regenerative blood. They can heal their wounds with their saliva. They are highly valuable commodities for all the properties that make them dangerous. Drank directly, their blood can transfer regenerative ability to the drinker if they lick their own wounds.
Dragons
Though the majority of pillar myths are centered around dragon progenitors, dragons have not been seen in the flesh for some time if they ever were at all. Thus, the majority of the common populace consider them to be a myth, though a rare few believe or claim to have seen one. There are also those who theorize that the pillars are not the benevolent gifts they appear to be but instead a proxy for an ancient conflict between the dragons. This is supported in books like the more mythologically driven Dragons which identifies the dragons by color rather than name and mentions a struggle between the equally matched Green and Red dragons. This is also supported by current geopolitical conflicts, like those involving LeShrac or the Westerners, that seem deeply rooted in notions of pillar superiority. Some scholars, like the Felspar consultant Syntyria, believe that the dragons don't care about us at all and use us as pawns.
In my travels, we have communed with Xisben in the wraith world and spoken to but not been allowed to see Veckra, who later offered us his blessing in our campaign to free Equinos. We have also personally seen and spoken with Chracio, about whom more can be read in the Sage's tomes.
My research reveals that the dragons have all agreed to a mutual contract for our* world, which is under protection of Den. Most dragons come from the table room (see note about source of dragons), or are children of other dragons (see note about dragon lineage). Azzur and Veckra are the only two primaries who are themselves children of Den. In fact, the pillars are calibrated particularly for the creatures of this world, which means it is possible that visitors from other worlds may be unable to attune unless the pillar has been reconfigured for their kind.
Research has also revealed that Dragons can be killed. By sparring with Chracio, Glad has learned obsidian weapons are effective at piercing dragon hide, unlike normal weaponry. But obsidian will only work on dragons not descended from Losken. In lieu of weaponary, magic can be used on dragons. They must ward or dispel it like anyone else.
*It's not clear if this contract holds for the other worlds that the dragons visit. But Den protects this one.
Dragons - Ascendance
Not all dragons start as they are. Some come to that cosmic position through a process called ascendance whereby they step outside of the natural order of things or become part of the natural order of things. One dragon known to do this is Vormyll, who was once a human woman in ancient times. More often than not, this process results in madness instead of ascendance.
Not much is known about them. They are considered creatures of myth similar in a way to ghosts. However, they are most definitely real and their blood can allow the drinker to enter their world of Dreaming, which is a mystical, metaphysical space of occasional insight. And almost certainly dangerous. Time and space there follow dream logic. And not all of the Dreaming's inhabitants are friendly.
Xisben claims that they are, technically speaking, not supposed to be in this world ... that their presence somehow violates one of the rules governing the world.
Foxes
I'll leave this one for Eierryn to fill out.
Goobers
Though referred to as 'Goobers' by the Silver Foxes, these large, tentacled beasts encountered deep within the Brenthian underground tunnels are of an unknown species. Goobers are aquatic, lake dwelling creatures who can also surface and traverse land. They have a great physical and constrictive strength and can jump to great heights. Goobers are highly intelligent creatures capable of using quasith, coordinated teamwork, and assessing whether a battle should be fled. When threatened, they may attempt to project terror with a menacing pose and a high-pitched, baby-like wailing.
Griffins
Griffins are mountable hybrid creatures with the upper body of a griffin and lower body of a lion. They can be found in Serosan and Brenthia and are used in both for aerial support and combat. The process to tame a griffin is a long one.
Og
An primitive deity worshiped in antiquity. Glad was able to commune with him through a makeshift blood magic ritual offering up his blood and ground Tusker bones. The bone dust seemed to be particularly effective. This ritual led to the appearance of a non-toxic, unidentifiable marsh plant with magic properties that eluded their expert scryers. Four days after consuming the leaves and tea brewed from the leaves, Glad had a dream vision of Og's place and was taught how to cast bones to Og in order to receive blessings of strength, speed, or protection. Once cast, an ominous fog creeps in and consumes the offering. In return, Og offers a simple "Good" heard only by the caster, and the caster is granted his boon. If anyone not under contract gets stuck in the fog, they risk their bones being devoured by the God as well. While the casts requires the caster to spell the sigil of the cast with bones, whole bodies can be offered up to Og and he will strip them of their bones, leaving behind only flesh and armor.
His original worshipers were from the swamp located across the bay from Kingsport. And his power doesn't trade in the forms of magic (like quasith) that are common today. He is many times older than Baishu. He is also older than Chracio.
Og does not like dream wraiths.
Payroks
A dead, subterranean Brenthian worshiped by his descendants.
Scarabs
These dog sized insects have hard exoskeletons and can swarm or fly in groups. They don't have any problem taking out human combatants. They are easily controlled by Chitters, though this telepathic coordination can be revoked.
Servant of Baishu
The Silver Foxes encountered this magical, but non quasith, construct that had persisted for an absurdly long 200 - 300 years. It was resistant to most of their counter attacks, including revocation, and only dispelled when a word of power once used for warding off an ancient pestilence was repeatedly chant. Father Benjamin claims that this word of power originates with Dhynn.
Xisben refused to share any info about Baishu, aside from offering that to find Baishu, one should investigate secret death cults.
Shadow Stalkers
Shadow Stalker is an unidentified, conceptual creature found in the Ruined Lands near Wharf 2. It doesn't appear tangible, doesn't read as a living creature, and is not subject to revocation. It is a hostile creature that latches on to the shadows of an area near its prey, waiting to entrap them. Conversely, it can also spread out to overtake the ground its prey stands on. It attacks its target by burning its target through some means of magical acidity. It can be harmed by reducing its area with light, such as with flash bangs.
Griffins are mountable hybrid creatures with the upper body of a griffin and lower body of a lion. They can be found in Serosan and Brenthia and are used in both for aerial support and combat. The process to tame a griffin is a long one.
Vorshen
A creature/being of some kind able to be contracted for blood magic. One of his servants is a flesh bound book with a talking face on its cover.
Wyrms
Wyrms are the smaller, armless, and more commonly encountered variant of dragons. They can be found in Serosan where they are a hunted. They are also consumable and used in various meals, e.g. wyrm steaks.