This quest is fairly easy. To start your quest find Farmer Walcott a little south-east of Sloeford, as indicated on the map above.
He will tell you that, recently, some of his cows were eaten by an out of control zombie. On top of that, the zombie upgraded himself from cow-eater to virgin-eater. Clearly he needs to be stopped.
To find the zombie, follow the yellow outline on the map above. If you do it right, you should find this house:
Inside the house is a person with an exclamation (!) mark above his head. Talking to him will turn him into a festering zombie. Your goal will be to kill it.
Once you have killed it, follow the same path back down to Farmer Walcott.
As a reward for your time and discretion, you receive some gold and experience. Add to that the loot from the zombie, and you got yourself a nice reward for a small job.
- Tip: If you have the quest Sacred 2:Tutorial Runemaster you can head North from the zombie to where the Runemaster's son is hiding, this saves running all the way out again.