From time to time animals will roam onto your farm. You may then publish these unique animals onto your Facebook homepage for your friends to adopt. So far there has been (In order of updates to Farmville):
- Black Sheep (Common)
- Brown Cow (Rare)
- Ugly Duckling (Average) - The Ugly Duckling turns into a swan after 4 days.
- Also there have been rumours circling the net about a mysterious Golden Chicken, which is said to be Super Rare. There is currently no proof on the internet that this is true.
Excerpt from: Wikipedia - click here for more info on Farmville