Lost In Space: "War of the Robots" Season 1 Episode 20, aired Feb 9, 1966.
Will and the robot come upon a dead "robotoid." Will wants a crack at fixing it while the robot wants it left alone or destroyed. In fact, something quite strange is happening with the Robinson's robot: he's developing beyond his programming, becoming more than just machine. Thanks to Will's repairs, the robotoid comes to life, but while it quickly presents itself as a subservient boon to the Robinsons, it secretly softens them up for capture by its distant alien masters, who are on their way.
Directed by Sobey Martin, Written by Barney Slater and Irwin Allen.
Starring: Guy Williams, June Lockhart, Mark Goddard, Marta Kristen, Bill Mumy, Angela Cartwright, Jonathan Harris and Robby The Robot.
Trivia:
The guest star was Robby the Robot from the movie Forbidden Planet (1956) and was used as a model for designing the "Lost in Space" robot.
In several scenes with the robotoid, the theremin-tinged music heard is from Bernard Herrmann's score for The Day the Earth Stood Still (1951), specifically those scenes featuring Gort, another robot.
