Kronos

The 1957 film Kronos was also marketed as Kronos, Destroyer of the Universe and Kronos, Ravager of Planets. It was made in two weeks on a budget of $130,000. Kronos is an alien robot that comes to earth to steal energy, so it attacks power plants, after stealing the mind of a scientist. The more energy the robot gathers, the larger it gets. The special effects were fairly good for its time, and the subject of limited energy supplies was prescient. WTM says it might be the first movie he ever watched. This colorized version is only 1:16:35 long; after that, it's someone's home movie, as if this was ripped from a VHS tape. (Thanks, WTM!)