Although physically similar to the T-800, the T-850 has a number of noticeable differences. For one thing, it appears somewhat older than the T-800 and displays less of the sense of humor exhibited by its predecessor. He almost seems to stand up for himself when he replied that he is a "cybernetic organism", not a "Robot", as John said. And although ordinarily programmed to follow any and all orders from Kate, it could override this default programming and trap her in the back of her truck against her wishes. It states that one of its basic subroutines deals with human psychology, and despite its lack of humor is still able to make an emotional connection with John when he fights the T-X's reprogramming of his systems and again later when he says goodbye to John.
Terminator 3: Rise of the Machines
It approached Connor in a veterinarian clinic where Brewster worked and took the two with him in the back of a van to escape the T-X sent to kill them. While driving, John asked him about its memories, assuming that this would have the same memories as "Uncle Bob". It stated that the Terminator sent from last time was a different unit and he was chosen by Skynet for infiltration due to John's emotional attachment.
At a graveyard, the three went to Sarah Connor's grave. The Terminator dropped her coffin to find weapons inside. When the police arrived, they got out and confronted the T-X. Later, at a campsite, the Terminator revealed that if the T-X failed to kill John and Kate, it would kill John's future officers as secondary targets, including Kate's father, Robert Brewster. While driving, the Terminator revealed that it was Katherine who sent the machine from the future, not John, because the Terminator killed John before being captured and reprogrammed by Kate.
In the Cyber Research Systems facility, the Terminator battled with T-1 units. It also fought the T-X, but lost. Controlled by the T-X, the T-850 began to attack John and Kate, but shut itself down to prevent itself from killing John. Later it rebooted, regained control of itself, and again battled the T-X at Crystal Peak. It managed to detonate its last hydrogen fuel cell to destroy itself and the T-X.
- The T-850 is played by Arnold Schwarzenegger
- The T-850 will meet Thomas, Twilight, and their friends in Thomas and Twilight Sparkle's Adventures of Terminator 3: Rise of the Machines.