They walk upright, averaging a height of about 5 meters, have thick skin covered in hair-like tendrils and a dense fur. Their skin coloration can change to match their surroundings which aids their ability to stalk their prey. They have clawed legs and sharp talons on their hands. The middle talon is elongated to form a blade that is used to open up a prey. Binocular vision and double rows of razor-sharp teeth secure their place as a top predator.
A highly territorial and exceedingly aggressive species, Isst have made quick work of any potential natural predators, leaving themselves at the top of the food chain. Mainly carnivorous, Isst have been known to supplement their diet with certain types of vegetation in times when prey is scarce. They are most often solitary creatures, though mating pairs have been known to work together during a hunt.
Isst are a favourite selection of big game hunters in the Par'tha Expanse, yet it is more often the hunter that ends up as prey.