Krikkit Robots

The Krikkit Robots are major antagonists in the Hitchhiker's Guide to the Galaxy novel Life, the Universe and Everything.

Origins
The Krikkit Robots were created by the Masters of Krikkit when they discovered alien life outside their planet Krikkit, and were determined to end the Galaxy, and the Universe too, if possible. The Robots were pure evil, concentrated in an artificial intelligence, sharing a hive mind to end all life they saw, regardless. The Robots were armed with a formidable array of weapons - one was a normal laser gun, the other was a supernova battalion, and another was a bomb and a bat, much like the cricket bat, which gave rise to cricket on planet Earth as a game, because other races had suffered much in the Wars and didn't want to use the memories as a game, but humans did remember the Wars, and for some reason turned them into a game, using the bomb and the bat as a cricket ball. The ball was ultimately modelled after the supernova bomb, developed by Hactar.

For the purpose of having cricket as a game, humans and the Earth have been shunned by alien life, and no other race will go to Earth.

The Krikkit Wars
The attack that the Krikkit Robots launched on the Galaxy was overwhelming and not underestimated. They destroyed countless planets, blew up suns, laid waste to civilization and razed cities and possessions. The Robots destroyed entire civilizations, and finally were tried by Galactic Judge Zipo Bibrox, and the Krikkit Robots were sentenced to eternal imprisonment on Krikkit until the End of the Universe. However, their Masters were aware of this, and sent the Robots out into space to revive them and start a new War.

The New Attacks
The Krikkit Robots attacked numerous civilizations on the Galaxy, including planet Earth, where they caused a mass destruction  at the cricket game, and also planet Squornshellous Zeta, where they stole Marvin's leg, and planet Argabuthon, where they stole the Scepter of Justice, and also ambushed a Party, where the Robots caused chaos and destruction before taking the Gold Bail. The aftermath of a Robot attack was summed up as: "Things were not going well, people were hating it, in fact, and saying so loudly."

The Krikkit Robots could teleport and they appeared with a noise like a hundred thousand people saying whop and then did the damage they could and teleported back out with a noise like a hundred thousand people saying foop.

Depression
Kidnapping Marvin the Paranoid Android was their big mistake because the Robots wanted his vast intelligence to govern the Krikkit computer, but Marvin sent out his vast depression to the computer, effectively ending the War. Marvin made the computer shut down, and made the Robots sink into gloom, and be unable to fight, because they went into war, suddenly thought "What's the point of all this? Why bother?" and then they would do fiendishly difficult equations, then sulk. The Krikkit Masters were confused because "Whoever heard of a Robot sulking?"

All the Robots were unable to fight when Hactar was destroyed, and Krikkit became peaceful.