Jak and the Magic Nano-beans - Carl Bowen - Bog

Mom wants Jak to sell Cow for scrap, but Cow and Jak have become best friends. So instead of selling the rusty old robot for spare change, Jak strikes a bargain with the scrap collector: if Jak and Cow can visit the Cloud Kingdom via the Space Elevator and get hold of some magic nano-beans, Jak can keep Cow safe and sound.