Risen
50 Achievements
GOG
Terror of the hens
20 chickens killed
1.9%
How to unlock the Terror of the hens achievement in Risen - Definitive Guide
As far as im concerned there's no penalty for killing the chickens, there's plenty to be found on farms throught the island, in the town and in the volcanic temple in the arena.
Just kill chickens when you see them from the get go, for the meat and experience. Farmers and people close by don't seem to mind one bit and will usually only comment about waving your weapon around. There are plenty chickens at the farm where you met Thomas and Tellur (who guided you to Harbour Town). The Don's camp in the Swamp also have several chickens, and they can be found around the Gutter part of Harbour Town. That should net you 20 or more chickens killed, and this achievement.
This guide was translated automatically.
On farms, chickens will spawn again after a while.