The Arkhea are a dangerous and prolific species of large, upright feathered raptors. Female Arkhea are typically larger and have black, faintly iridescent-blue feathers, and are usually more aggressive to people than male Arkhea. Male Arkhea are usually smaller and bear bright feathers of a variety of colors, but weave elaborate drapes of leaves and foliage to hide themselves during hunting. Both sexes  have long, elaborate feathered tails that they use to signal to each other. They have long snouts with neat rows of sharp teeth, save for long, needle-like incisors that can inject a strong paralytic venom. Their cat-like eyes come in quite bold colors, either blue, gold or red. They have hands with three fingers and one opposable thumb, and have dexterity comparable to humans.

Arkhea are the most intelligent non-sapient animal species on Elstren, barring those enhanced through some kind of magic, and are highly successful predators outside of that. They don't create tools as often as a sapient species likely would, and do not display traits of sapience such as abstract thought or a very high degree of self awareness. They can, however, learn to use advanced tools with some work such as swords and even firearms, and some rare individuals can even emulate some complex human behaviors such as deliberate planting of crops if they observe such behavior extensively.

A distinct trend is that some Arkhea are born with noticeably larger brains than others. Arkhea are strongly social pack animals, and theses individuals occur at a rate such that a pack will maintain roughly one to two of them at a time assuming stable conditions. These gifted Arkhea tend to help guide their pack, and because they are also the most dangerous their rule is rarely contested.