Zombie Cows live on venus, eat fire, and produce chocolate milk. They aren't very friendly creatures and only one person in the world breeds them. Zombie cows cannot survive off of Venus however.
Your chocolate milk probably came from a Zombie Cow!
What happens if a dead cow isn't hauled off to be processed into meat fast enough. They are usually green and smell like mold. Certain people can turn into Zombie Cows when murdered, if they are fat enough or are extremely dim-witted.
I clubbed the cow in the head and it fell like a rock, but no one came to cut it up so it turned into a Zombie Cow.