Arnold Schwarzenegger is a famous Austrian-American actor and the former governor of California. He appeared in the episode "It's a Jersey Thing", where he refused Randy Marsh's plea for help against the Jersey invasion. He is mentioned again in "T.M.I." where Butters and the boys discuss his love child scandal which only made the headlines a day (if that) before the episode aired.
Arnold wears a black suit, white undershirt, and purple tie. He also has a tooth missing.