They appear like Humans with pale greenish or yellowish skin, and hair patterned in shades of green and yellow. On the top of their heads there are several pebble-like nodules, which will fall down one by one as the Argolin ages. When the last nodule falls the Argolin's body will deteriorate in a matter of seconds, killing them immediately. This strange metabolism was actually one of the consequences of the devastating radioactive warfare that fell on their planet, with another one being that they are irreversibly sterile, and therefore face danger of extinction.