Here is the full list of all 20 John The Zombie achievements.
Score 2000 points by causing chaos.
Win the second race.
Catch one big fish.
Win the third race.
Win the first horse challenge.
Win the second horse challenge.
Win the first race.
Finish the campaign.
No agressions for 10 minutes.
Learn 10 skills.
Attack 5 cops.
Kill 20 zombies with a car.
Score 50 points in basketball.
Eat 50 brains.
Score 1000 points by causing chaos.
Eat 10 cow's brains.
Score 500 points by causing chaos.
Eat 30 brains.
Learn 5 skills.
Eat 10 brains.