T-1000 (Judgment Day)

The T-1000 is a liquid-metal android, whose main goal is to kill John Connors in the past.

Story
As the super-computer Skynet became self-conscious, it started mass-producing the terminators, in order to wipe out the humans from the face of earth. A human resistance was leaded by John Connors, who organized the survivors of the Judgement Day to fight the machines. Skynet then sent a terminator to the past to kill Sarah Connors before she gave birth to John. As the first terminator failed, Skynet took the next step and sent another terminator, the prototype T-1000, to kill John while a child. John managed to capture a terminator and sent him to the past as well to protect himself in the past.

Personality
Altough the T-100 is a heartless machine, he shows some traces of cynism and sarcasm.