It will not become a "lifeless" zombie if harvested when you have no life available to give it.
It makes your crops worth double their money but I don't know what happens to fertilized zombies
you get a zombutterfly
though nothing will happen :p
you have to eat a chicken testicle
yes
Nothing
To get that farm banner on Zombie Farm, you've got to win an invasion and have some luck with the loot you get.
You cant. Thats in Plants vs. zombies, not zombie farm.
you cant .....
You buy it from the store.
shot it with an arrow
surround the zombie with plants