The Robot Probes are the secondary antagonists of DreamWorks' eighteenth full-length animated feature film Monsters vs. Aliens. They are enormous cycloptic robots that serve Gallaxhar, sent over to Earth to find the Quantonium as part of Gallaxhar's plan to destroy life on Earth.
The robot probes were possibly created by Gallaxhar originally as miner droids to get Quantonium. They are roughly the same height as Insectosaurus, only slightly taller. They are also protected by an impenetrable deflector shield which blocks all forms of attack, making the robots immune to any of the military's weapons and their feet can crush anything beneath them apart from B.O.B.. Though their weaponry consisted of powerfully strong arms and claws that were strong enough to haul its own heavy weight body out of a crater or tear down a tall building, they were not strong enough to counter the strength of Ginormica. They even possessed a phasoid blaster in its eyeball, but it was only seen in use during the Game. Besides being used as probes, Gallaxhar also intended to use them as troop transports to transport his clone army down to Earth.
A Robot Probe first appeared after being sent over by Gallaxhar, crashing down into Earth. As the military mobilizes to its location, the President attempts to make the first contact with the probe, but this failed as the probe goes on a rampage, forcing the military to fight back. Despite the military's best efforts to use air support and other weaponry, they are forced to retreat after realizing that their weapons remain ineffective against the probe's shield. This forced the government to release Ginormica and the monsters and use them to stop the probe in exchange for their freedom. With that in mind, Ginormica and the monsters work together to destroy the probe by using the Golden Gate Bridge to collapse and decapitate it.
Despite the probe's destruction, Gallaxhar was able to pinpoint the Quantonium's location inside Ginormica (as it was the main cause of why she became a giant in the first place). To that end, Gallaxhar kidnaps Ginormica and extracts the Quantonium to reduce her back to normal size, intending on using the element to create quick clones to launch a full-assault on Earth. Fortunately, the other monsters come to the rescue, forcing Gallaxhar to set his other robot probes to stop them at all costs.
Thinking wise, Ginormica is able to surf herself away from the probes, causing their deflector shield to act up and make them crash with others. This allowed Ginormica to regain the Quantonium and escape with her monster friends, while Gallaxhar's ship starts to self-destruct, killing Gallaxhar and destroying his remaining robot probes, resulting in their extinction.
The Robot Probes are mostly the evil counterpart of the Iron Giant from the 1999 film of the same name. When overpowering military forces, the Robot Probes use shield to remain ineffective against firepower, though they don't use laser weapons as a means for defense and use its own arms to destroy them.