The Philons Bird and Snake was created by Philo of Byzantium. Although sometimes he was also called Philo Mechanicus. Philo was a Greek mechanics writer and engineer sometime during the second half of the 3rd century BC.
How Did it Work? (Animation)
A snake is swimming in the water. When water is filled in through the small holes on the right, the water rises and the snake rises, heading towards the birds.
The great bird now defends its little fellows. The rising water moves the bird and swings it's wings.
By decreasing the water, the snake hides somewhere and the bird, now sure of its success, goes back to the little birds. The presentation is finished.
The second half of the animation below was not part of the presentation. It is simply what the presentation would look like if it was invisible. Making it easy to see behind the scenes and uncover how the ancient invention worked.