Robot Aliens were huge robots that were minions of the Mothership. They resembled a typical UFO, except with long legs and ray-guns attached on the sides, and were piloted by aliens resembling stereotypical 'Greys'. They would usually appear in groups, with one chasing Giant Clank, attempting to electrocute him, and any others firing at him with red lasers. These Robots either spawned randomly around the moon, or were deployed in groups of four by the Mothership. Destroying them would also replenish Giant Clank's health.
- Ratchet & Clank: Going Commando (first appearance)