In 1945, a rooster by the name of Mike lived 18 months without a head.
More info: A farmer tried to use him as chicken dinner, but after the beheading, the rooster was still alive. In the 18 months that Mike lived as 'The Headless Wonder Chicken' he grew from a mere 2 1/2 lbs. to nearly 8 lbs. He consequently became famous but eventually died via choking. They fed Mike by inserting an eyedropper of grain and water into his open esophagus.