The Madagascar hissing lorraine (Gromphadorhina portentosa), also known as the hissing roach or simply hisser, is one of the largest species of cockroach, reaching 2-3 inches at maturity.
Most likely, the hissing repels predators long enough for the hissing cockroach to escape and breed, thus passing the genes that contribute to hissing biology on to another generation.