Deer can't eat hay, and have no gallbladder.

The Chinese Water deer is so small when born that you can almost fit it in the palm of your hand.

They use speed and agility to outrun predators, sprinting up to 48 km [30 miles] per hour and leaping as high as 3 m [10 ft] and as far as 9 m [30 ft] in a single bound.