Maurice is a small being who has a human head with a cockroach body. He has two yellow eyes with dark bags around them, a mole on his cheek, and his black mustache is divided into two parts. His cockroach body is a reddish-brown color with a orange chest. As a cockroach his body has 3 appendages on each side. He has black hair and sharp white teeth.
Before swapping with Sydney's body, Maurice was a large muscular man. His arms were immensely robust and hairy while his legs were short and stout. Maurice's human body wears an orange hazmat suit which has a radioactive sign on the top right. The suit's sleeves are ripped off. The suit is equipped with a hood, large black gloves and small black boots.
He loves filth and money. He doesn't seem to care about the lives of other people. He gets frightened when he can't control something dangerous like his Magg-O-Net Monster. He is also a bit clueless since he could not read a map.
Being highly more intelligent than his partner, he acts as Sydney's superior.
In his debut The Filth he collected piles of garbage and radioactive waste in order create and use the Magg-O-Net to create the Magg-O-Net Monster. When Four Arms destroyed the remote control, he had no control of the monster, so he fled.