Zombie bums from Uranus

"Aided by little more than a squeezy bottle of tomato sauce, a rudimentary grasp of the hokey pokey and three of the oldest bum-fighters on the planet, Zack and his bum are fighting to protect the Earth against an invasion of some of the smelliest and most dangerous bums ever to pollute the universe."
"In the deepest, darkest corner of the solar system lies an enemy more terrifying than the people of Earth could imagine. Vicious warriors who will let nothing stand in the way of their crusade for galactic domination. They're cunning. They're ruthless. They're zombie butts from Uranus! Earth has only one hope for salvation. Zack, a twelve-year-old who wants nothing more than to wash his hands of the whole butt-fighting business. But Zack cannot shirk his duty--and he cannot escape his destiny. Joined by an assortment of butt-fighters, and his own brave butt, Zack will do what he must to rid the earth of these stinky space invaders."@en
""Zack Freeman is back ... and so is his bum. Aided by little more than a squeezy bottle of tomato sauce, a rudimentary grasp of the hokey pokey and three of the oldest bum-fighters on the planet, Zack and his bum are fighting to protect the Earth against an invasion of some of the smelliest and most dangerous bums ever to pollute the universe: zombie bums from Uranus! Can they prevent the unthinkable -- total zombie-bummification of the world?"--Back cover."@en