Grunts possess the ability to speak. However, as their lower jaw has been distended to an unnatural length, most of what they say is instead guttural growls, hisses and noises, with the occasional garbled attempts to speak. Their visual and audio perception appears uninhibited. Their intelligence is questionable at best. They won't notice Daniel if his head is hidden from sight and he's not in the light. However, should he make a loud noise, the grunt will bring its hands to its mouth, seemingly in shock, before searching the area for him.
Grunts are humanoid beings with seemingly pieced together bodies. Stitches and open scar-like wounds cover their pasty and stained skin, with bandages wound tightly around their feet and other parts of their torso. Their "skin" also functions as their clothing, as shown by the skirt-like protrusion around their waist and the sound of rubbing skin made when they walk. Their heads are malformed, with a distended jaw that hangs over their torso, stretched to an absurd length. There are clumps of hair still attached to their head. Their eyes are large, bulging and reptilian. The Grunts are missing their fingers on the left hand, which have been replaced by crude blades, which serve as the creature's primary weapon, and are stained with blood; whether this means that the grunt has attacked another person or other type of animal before or that the blades were attached in such a way that it caused the Grunt to bleed is unknown.