Captrees are giant fungi that are the main component of the world's forests. They have smooth gaps, bioluminescent gills, tall trunks, and banyan-like roots that extend some distance underground.

The Master of the Wood is a unique fungus of a different species than the regular captrees, with a white ruffled cap resembling an oyster shell, a veil, and a trifurcated base. It is the only one of its kind.

Greater mushroom lamps grow on the forest floor, usually in long rows that appear to form paths, though they may not lead anywhere.

Lesser mushroom lamps only grow in sheltered caves and other crevices.

Moss grows exclusively underground, and generally on basalt.

Ferns grow on the forest floor and in caves when standing water is present.

Squirrelraptors are medium-sized predators, roughly human height. They are furry, with squirrel-like heads and tails, but the proportions and clawed feet of a dromaeosaur. They are curious and not especially aggressive, and mostly hunt small prey, using their "killer" claws as a climbing aid.

The Bandeen is a climbing animal like a cross between a Psittacosaurus and a raccoon. It has a psittacosaur-like head shape, with two small horns over the eyes, and mask-like markings that extend down the neck and shoulders. The body is covered in gray fur and the tail is bushy and banded like a raccoon. It is a herbivore that lives in the Captrees and rarely comes down to the forest floor except to nest in small caverns or migrate to a new tree.

The Bandolemur is a smaller, kitten-sized relative of the Bandeen, with an Oviraptor-like beak shape, small nubs over its eyes like Maiasaura, a galago-like body, and a glowing tail tip. It eats mainly insects, attracting them with its glowing tail and then capturing them with lightning-fast reflexes. Bandolemurs are very social with their own kind, but skittish around any larger creatures.

Staghorns are agile herbivores found on and near the forest floor. They are kangaroo-like, with deerlike snouts and ears, small hornlets covering most of the skull roof, and two longer forked horns or antlers behind the eyes. Their backs and long tails are protected by three rows of osteoderms. They move on the ground and between low perches by bounding, and have a modest climbing ability.

The Shieldbok is an elk-sized herbivore with two large bony "fins" protruding from the top of its head and vivid blue stripes. Their bodies are loose-skinned like a cat, with soft hoofless front feet and two-toed back feet. Males use bioluminescence as a threat display and compete with one another by butting heads. Their blue stripes light up so brightly that, against such a dark backdrop, they appear almost blinding.

The Mudflapper is a racing biped generally found near freshwater. It resembles a cross between an ornithomimid, a duck, and an oversized jacana, with a throat pouch and immense lobed toes. Males are colorful, with blue on their faces and yellow streaks on the neck and throat, while females are simply brown with spotted backs. It is named for the sound its feet makes when it runs.

The Hip-yip is a bison-sized, aggressive predator found along rivers. It is semiaquatic, sometimes ambushing prey at the surface like a crocodile, but most of its diet consists of large fish.

The Tusker is a shy, solitary, slow-moving herbivore that forages on the forest floor. It has a very large, rotund body, especially in the hindquarters, and a head shape like a tapir, though the nostrils are camel-like and the lower jaw ends in a massive single tusk-like beak. It uses this beak to dig for roots and other food items. Its body is covered in camouflage markings like a spotted chevrotain; it has no real odor and its main defense is to simply not move and wait for danger to pass.

The Brontowl is the world's largest predator. It is a massive owl with a long, deep beak like an auk, with a sharply pronged lower jaw, and two very long plumes on its head. It is about 2.5 times the size of Argentavis, but has a proportionately shorter wingspan.

The Lantiel is a small, social bird found high in the canopy, where they feed on captree gills. Their glowing cheek spots help illuminate their surroundings. Males have yellow and black stripes on the back of the head, while in females they are gray and black.

The Grendel toad is so named because of its terrifying, growl-like croak. It is a little smaller than a housecat and has a Tyrannosaurus-like face and two-fingered forelimbs. Its tongue is short but bioluminescent and very sticky; it can invert its throat pouch like a pelican to make the tongue more prominent. Insects that touch the inside of the toad's mouth become trapped.

Gliding frogs are small arboreal froglike amphibians that spend most of their time living in captree groves. They have gliding membranes on their sides like Draco lizards and a long tail with a flange at the end, similar to some pterosaurs. This enables them to not just jump great distances, but to actually glide from one tree to another.

Running frogs are small terrestrial froglike amphibians that have no forelimbs, and run on their hind legs in a manner similar to small birds or theropod dinosaurs. They prefer not to swim but will bathe themselves in puddles with vigorous splashing motions, like birds in a birdbath. The Torrent running frog is found in lowlands near freshwater.

The sunset running frog is found in sheltered areas around caves and rocky crevices.

The rain pool running frog is found around the bases of waterfalls.

The wood ghost running frog is found in exceptionally foggy places.

The Snapfish is a large, 3-foot predatory marine fish with a dolphin-like beak and a very long dorsal fin. It is a very fast, maneuverable hunter.

The Longfish is a herring-like marine fish with colorful fins, banded with yellow, black and white.

The Crookjaw is an enormous Leedsichthys-sized predatory fish, the apex predator of the marine ecosystem.

The Creekmaw is a salmon-like freshwater relative of the Snapfish. It is a little smaller, around 2 feet in length.

The Creekfish is a trout-like freshwater fish related to the Longfish.