Mike the Headless Chicken

Scientific American gives a little weird history lesson:

Also known as Miracle Mike, Mike the Headless Chicken was a plump, five-year-old cockerel when he was unceremoniously beheaded on 10 September 1945. Farmer Lloyd Olsen of Fruita in Colorado did the deed because his wife Clara was having her mother over for dinner that night, and Olsen knew she’d always enjoyed a bit of roast chicken neck. With that in mind, Olsen tried to save most of Mike’s neck as he lopped his head off, but in doing so, he accidentally made his axe miss Mike’s jugular vein, plus one ear and most of his brain stem, and to his surprise, Mike didn’t die.
In fact, Mike stuck around for a good 18 months without his head.
Immediately after it happened, Mike reeled around like any headless chicken would, but soon settled down. He even started pecking at the ground for food with his newly minted stump, and made preening motions. His crows had become throaty gurglings. Olsen, bewildered, left him to it. The next morning, when Olsen found Mike asleep in the barn, having attempted to tuck his head under his wing as he always had, the farmer took it upon himself to figure out how to feed this unwitting monstrosity. Mike had earned that much.
All Olsen had to do was deposit food and water into Mike’s exposed oesophagus via a little eyedropper. He even got small grains of corn sometimes as a treat.
Mike’s unlikely survival has everything to do with how his skeleton was shaped, Wayne J. Kuenzel, a poultry physiologist and neurobiologist at the University of Arkansas, told Rebecca Katzman at Modern Farmer. Because a chicken’s skull includes two huge holes for holding its eyes in place, its brain fits snuggly into the remaining space at a 45-degree angle. This means you could slice the top bit of the brain off while still leaving a good portion – with the cerebellum and the brain stem – behind. “Because the brain is at that angle,” Kuenzel told Katzman, “you still have the functional part that’s so critical for survival intact.”
That Mike’s cerebellum was positioned below his massive eye holes and was spared by Olsen’s axe means he was still perfectly able to perform basic motor functions and breathe. He was just a little bit more clumsy now because, you know, he had no eyes.