In Terminator 2: Judgment Day, the liquid-metal Terminator is designated the T-1000.
The T-1000 is an advanced infiltrator made from a mimetic polyalloy, a fictional liquid metal that allows it to change shape. It can imitate people after physical contact, form blades from its limbs, and recover from damage that would destroy a conventional machine. Robert Patrick plays the T-1000, using a notably calm and athletic performance.
The film contrasts the T-1000 with the reprogrammed T-800 played by Arnold Schwarzenegger. The T-800 is a mechanical endoskeleton covered by living tissue, while the T-1000’s body is presented as a single shape-shifting material. This distinction is central to the chase and action scenes.
The T-1000 is not the same model as the T-X from Terminator 3 or the T-800 from the first two films. Its designation refers to a different generation and design concept within the fictional Skynet machine army.