The Terminator is a fictional cyborg first introduced in James Cameron's 1984 blockbuster film of the same name. Portrayed by Arnold Schwarzenegger, the Terminator first appears as an antagonist, built by Skynet - an artificial intelligence from the future - to carry out covert assassination missions. Though appearing completely human, the T-800 models are actually robotic endoskeletons covered with living tissue. In various movie sequels, the Schwarzenegger character becomes a protagonist who assists humanity in battling other Terminators as they attempt to change history and prevent Skynet's awakening, known as Judgment Day.