Cerberus was a neutral monster. He was neither good nor evil. He was wild and ferocious, yes, but to characterize him as a purely evil creature seems a little too much. Soon after his birth, he was assigned the task of guarding the entrance to the underworld. He certainly didn’t show any mercy to the dead, who attempted to escape, or to the living who sought to enter Hades’ realm. Cerberus was a vigilant and ruthless watchdog, proving his worth and keeping the underworld unbreached. Therefore, he cannot be considered evil beyond the aspects of his duty.