Zombies and Other Inconvenient Truths
an excerpt

The fourteenth great pirate, ninja, zombie and robot war began when the pirates built a trebuchet outside the great robot city of Eidolon, and launched a cow at it. The pirates missed, since they had a modest celebratory glass of rum to welcome the beginning of the war, following their daily ration of a bottle each. As a result, the cow landed on the zombie shamble (zombies do not build cities) of Wherever, fourty-three kilometres distant, landing on the great zombie philosopher, Gavin, and the other great zombie philosopher, Ellie. The zombies did not mind this at all, because they were philosophers and zombies do not have brains, so Gavin and Ellie spoke a lot about nothing much worth listening to at all, and all the other zombies paid no attention because they were too busy spouting "grr" and occasionally "arg". However, they did find the cow brains moderately tasty, so they calculated the likely launch site of the cow based on its incoming trajectory and so discovered the pirate camp (who had by then managed to hit the great robot city of Eidolon, although they had run out of cows and had to resort to a volley of shovels, one of which decapitated a robot and really pissed it off), and attacked once they discovered the pirates had run out of cows. It is a little-known fact that zombies have highly advanced mathematical skills; this is how zombie hordes are always able to predict the locations most likely to contain survivors, and so swarm them with overwhelming numbers, no matter how clever the survivors think they have been in finding a safe spot to hide.