This is a book about two aliens who've decided their purpose in life is to conquer the galaxy.
The only problem is, they're really bad at it. Really, really, really bad at it. Hilariously bad.
Got a planet that wants to elect them president? Kaput and Zosky will shirk their responsibilities and run away as quickly as possible. Got a planet filled with gamblers? Kaput and Zosky will lose every time, and get addicted in the process. Got a planet inhabited by vampires? Kaput and Zosky will accept a dinner invitation (of course, it turns out that they're the dinner).
How much does incompetance hinder plans to conquer the galaxy? Quite a lot, it turns out!