Krikkit is am immensely xenophobic planet. The people of Krikkit are just a bunch of really sweet guys who just happen to want to kill everybody.
The first Krikkit attack on the Galaxy had been stunning. Thousands and thousands of huge Krikkit warships had leaped suddenly out of hyperspace and simultaneously attacked thousands and thousands of major worlds, first seizing vital material supplies or building the next wave, and then calmly zapping those worlds out of existence.
They utilized millions of lethal white robots. These had really struck terror into the hearts of everyone who had encountered them- in most cases, however, the terror was extremely short-lived, as was the person experiencing the terror. They were savage, single-minded flying battle machines. They wielded formidable multifunctional battleclubs that brandished one way knocked down buildings, brandished another way fired blistering Omni-Destructo Zap rays, and brandished a third way launched a hideous arsenal of grenades, ranging from minor incendiary devices to Maxi-Slorta Hypernuclear Devices that could take out a major sun. Simply striking the grenades with the battleclubs simultaneously primed them and launched them with phenomenal accuracy over distances ranging fro mere yards to hundreds of thousands of miles.
The planet of Krikkit was sentenced by the Galactic Court to be encased for perpetuity in an envelope of Slo-Time, inside which life would continue almost infinitely slowly. All light would be deflected around the envelope so that it would remain invisible and impenetrable. Escape from the envelope would be utterly impossible unless it was unlocked form the outside.
When the Universe came to its final end, when the whole of creation reached its dying fall, and life and matter ceased to exist, then the plant of Krikkit and its sun would emerge from its Slo-Time envelope and continue a solitary existence, such as it craved, in the twilight of the Universal void.
The Lock would be on an asteroid that would slowly orbit the envelope.
The Key would be the symbol of the Galaxy- the Wikkit Gate.
One lost Krikkit warship was able to unlock the Slo-Time envelope after assembling the pieces of the Key. Marvin was linked to the central intellgence core of the Krikkit War Computer.
It has been said that on Earth alone in our galaxy is Krikkit (or cricket) treated as a fit subject for a game, and that for this reason the Earth has been shunned; this only applies to our Galaxy, and more specifically to our dimension. In some higher dimensions, they feel they can more or less please themselves, and have been playing a peculiar game called Brockian Ultra Cricket for whatever their transdimenional equivalent of billions of years is.