Most of the biological life on Posea seems to be similar to that on Earth: macrobiotic life takes the form of plants, fungi, and animals, which have their own internal taxonomy. This page wont explain the general details of these distinctions (as you are likely already familiar with the basics, or could easily search for them on wikipedia), but instead will focus on individual species mentioned in the comic itself. Unfortunately, very few of these species receive actual names.
Unnamed Tree Species – really the only information about these is that 2 trunk trees have some sort of built-in fire resistance (since the Guardians already know this about them as early as day one), and that 1 trunk trees are more suitable for use in creating fire.
Unnamed Fungal Species – Greenish-brown stem, gills, and cap, multi-stalked, and has light blue bubbles on the top of the caps. Notable for its Psychoactive properties.
Ploki – a species of small, fruit-bearing, flowering plants which were first domesticated by Ka & Moi (see species name link). The fruit they produce can be seen here, and is described as being sweet. My best guess at an Earth equivalent would be a mango without the pit.
Kabug – an insect with two antennae, a turquois cap on its head, a long, slender neck, a thin striped body with six stilted legs (three on each side) with a pair of translucent wings, and a slightly bulbous, striped thorax. It appears to be slightly bigger than the size of a paw. Also seen here.
Selgat – A large herbivore species. They are covered in fur of two shades of blue except for their sharp beak and piercing yellow eyes. They have two tufts that stand straight up like ears, and a much larger tuft at the end of their impressively long tail.
“Selgats are strong and have great memory, but they are quite lazy…” – Tan
Unnamed Quadruped Species – Similar in appearance to an Alpaca except for a few notable differences: their fur is tie-dye (mostly yellow hues), they have a long tail with a fluffy tuft of fur at the end, and they have paws instead of hooves.
Unnamed Quadruped Species – A small mammal of a size/appearance approximate to a domestic, white, longhair cat; except for the long black whisker/horns coming from between its ears.
Unnamed Quadruped Species – Carnivorous mammal similar to a mix between a fox and a hyena. Its head appears like a fox: reddish-orange top with large, pointed ears with white-beige interior, pointed cheek tufts, and a white-beige maw) with a white-beige stripe running from the top of the head down the mane along the neck. The rest of its body is like a hyena: large tufts of fur near the joints, majority reddish-orange with a white-biege belly with spots around the edges, and a long, slim tail.
Kwan – aquatic, bioluminescent creatures that have no Earth-like comparison. Their bodies are long, thin, and black in color with two large, maneuverable fins and one transparent stationary fin about their midsection, a split fin on their tail, and two long, glowing antennae about the base of their neck. They have bioluminescent spots along their body, specifically: one on the bridge of their nose, two above each eye, two on the dorsal side of their arm-fins, and one large spot on the base of their tailfin.