"I'll tell you what else is amazing...That you and I can be here like this and converse in a German accent for hour after hour and neither one of us is German."
- Dr. Mathew Rath to KAOS Agent Cronin.
A former assistant curator at the Washington Zoo, fired for conducting unauthorized experiments with apes.
While continuing these experiments with chimpanzees, monkeys, baboons and gorillas, Dr. Rath is paid by KAOS to kill CONTROL agents. A lonely man for years absorbed in his work, he laments that he is without friends or companionship and intends to use the money to bring himself feminine companionship - by building a woman in his laboratory.
The killings he accomplishes by means of "Chucko", a trained ape who he has "through a series of injections" transformed so that he looks human but in his brain retains the "savagery and the killer instinct of a gorilla", infiltrated into CONTROL in the guise of Chuck Armstrong, Agent 77.
Seven CONTROL agents are murdered in this way before Rath is finally located and arrested in his apartment/laboratory/menagerie when the people who live downstairs complain.