Raw Chicken

Raw Chicken is a food item added in the 1.8 "Adventure Update". Formerly a chicken would only drop a feather, but now a Raw Chicken is dropped (usually along with a feather), and can be obtained by killing a chicken with a sword, or with a bow and arrow. The Raw Chicken heals 1 unit of Hunger points. It can be cooked into Cooked Chicken with a furnace. Chickens drop 1 Raw Chicken upon death. If you eat one of these without cooking them first, you have a 30% Chance of getting food poisoning.

Behaviour
Raw chicken has a 30% chance of giving you food poisoning, which is the reason why it's better to cook it first. However, food poisoning just barely counteracts the raw chicken's food saturation, and will not even drain half a food point, making it a very minor drawback, especially when eating multiple raw chickens at once. Chickens drop a raw chicken upon death, and a Cooked Chicken if killed in a fire.

Trivia

 * The poisoning effect is most likely based on the real life disease Salmonella, which is notorious for being present in uncooked meats, more commonly raw chicken and fish.
 * Because food poisoning does not stack, and because raw chicken has a very high food saturation value, eating multiple raw chickens at a time will easily restore more hunger than the poison can take away.