In the third novel in the Hitchhiker's Guide to the Galaxy Trilogy, Life, the Universe, and Everything, we are introduced to the planet Krikkit, and it's mighty white robots who are bent on detroying all life in the universe.
Created by the inhabitants of the planet Krikkit, who, upon discovering that there were other inhabitants in the universe, became violently xenophobic and attempted to wipe out all other races.
After a longish war, the Planet Krikkit was sent into a dimensional pocket where they would remain until the end of the universe, at which point they would be freed to live as they chose.
The Krikkit weapon of choice were gleaming white robots using cricket bats and explosive red balls.
In Life, the Universe, and Everything, the robots attempt to free the planet from its rift and destroy the galaxy, and are blocked in this pursuit only by Arthur Dent, Marvin, and the rest of the Hitchhiker's crew. | 
