The "Transformers" movies, directed by Michael Bay and starring Shia Lebouf, are based on the Hasbro line of toys and popular '80s carton series. Both Autobots (the good guys) and Decepticons (the baddies) are classic examples of alien robots. In the second film, "Transformers: Revenge of the Fallen," it is revealed that several robot alien scouts were sent to Earth decades before the plot of the first movie unfolds. The cast meets one of the alien robot scouts, Jetfire, who is depicted as an elderly (voice and mannerisms) robot. Jetfire sacrifices his spark and parts to fix the leader of the Autobots, Optimus Prime, prior to a final battle scene.
The 2000 film, "Red Planet," starring Val Kilmer, Carrie-Anne Moss and Tom Sizemore, features an alien robot scout sent from Earth to the planet Mars (this robot is an alien to the planet Mars, but native to Earth). The robot is modeled after the real-life Mars Rover vehicles used for the same purpose. The rover in "Red Planet" has capabilities that are only possible in movies, such as a battle mode which allows the rover to morph into a machine with arms and legs as well as sharp cutting devices. In the film, the rover goes haywire, killing one of the crew members.
"Battlestar Galactica" is a science fiction franchise that began with a TV series in 1978 and was revived in 2003. The story deals with an intergalactic war between humans and a cybernetic (robotic) race of aliens called Cylons. Normally, Cylons appear as artificial metallic robots, but they gain a strategic advantage by manufacturing versions of themselves that appear to be human. The human, skinned Cylons infiltrate humanity as scouts and spies in an attempt to win the war.
Gargantus is an alien robot scout that first appears in the Marvel Comics title, "Iron Man." Gargantus was made by an alien race that sent scouts to Earth during the caveman era. As a result, they fashioned Gargantus to appear as an Earthling of that time period, however in modern times, he was out of place. Gargantus had an ability to hypnotize people and succeeded in taking over a town as the first stage in a plot to overthrow the Earth. Iron Man saves the day by breaking Gargantus up into dozens of pieces.