Mammoth is a gigantic, feral, ape-like creature who was previously a human postal worker from Covington, Indiana, nicknamed "Mammoth" due to his large size. After he was fired from his job, he flew into a rage and killed many of his colleagues and customers in a bloody rampage. He died from committing suicide afterwards by shooting himself. His history may be a reference to the term 'Going Postal', which was a term derived from a series of incidents from 1983 onward in which United States Postal Service (USPS) workers shot and killed managers, fellow workers, and members of the police or general public in acts of mass murder. In his ending he kills an old lady and her dog and stuff their corpse in the mail box.