The head features recessed eyes protected by bony ridges and a wide jaw filled with razor-sharp teeth. A row of sharp spines runs from the crest of the head down to the base of the spine. Growler hides come in a wide variety of colors based on their pack, diet and environment, ranging from white through black, with red and blue colors predominate. Growler hides are often striped, stippled, or mottled with other colors. Body hair is rare, usually apparent only on chieftains or specific breeds.
Growlers reproduce sexually, and have males and females called bulls and mommas, respectively.
Though less physically imposing than bulls, mommas compensate by embracing a much meaner attitude, and are generally more hostile than males. Female pups are nearly indistinguishable from male pups until they reach about two or three months old, at which point the female traits begin to manifest in full. Growler pups are born live, and fully capable of hunting just minutes after birth. Growlers mature rapidly, taking about eleven months to go from pup to full-grown adult. Growler body and muscle tissues are extremely dense, layered to protect the vital internal organs.