An anathak has features that equally resemble a horse and a grasshopper. It has a hard green shell with a large number of hairs resembling fur. Its neck is long like a horse, but consists of a single shell segment. Its short, hollow antennae resemble a horse's ears when swung back, but can also swing forward to smell things on the ground. It has six legs, with the rear pair longer and more powerful than the others; the rear pair is partially merged with the abdomen at the hip to help support its weight. The thorax is long, but the insectoid division between thorax and abdomen is still visible. Its feet terminate in hooves, but these hooves are primarily made of chitin rather than keratin.
Anathaks are fast runners with good endurance. Their extra pair of legs breaks their air time into three rather than two segments when galloping, so they waste less energy bouncing up and down than a quadruped. Their powerful hind legs not only allow them to accelerate quickly, but also cause them to lose less speed when pulling a load (such as a hovercart) than most other animals.
Their hard cuticle gives anathaks other advantages. They retain water better than most mammals, which is an important advantage in arid or semi-arid terrain. The cuticle also serves as natural armor, reducing the need for barding when used as a military mount. The prevalence of anathaks as a beast of burden is largely a side effect of their extensive breeding for military use.