The Giant Isopod can grow from 7.5 to 30 inches long. The size that has been recorded keeps changing. They are portected by an exoskeleton composed of overlapping segments. They possess the ability to curl up into a "ball".
Giant Isopods have two pairs of antannae. They are usually pink or lilac in color. The antannae help them figure out where they are going. They also have four sets of jaws, but a very slow metabolism.
Giant Isopods are scavengers usually in depths of total darkness where pressures are high and temperatures are low. They are adaptive to long periods of famine.
Scientists don't know why the deeper you go in the ocean the larger the Isopods are. The persumption is the huge size might help them survive the extreme pressure.