Giraffe

The giraffe is the tallest mammal on earth with an average height of 16-18ft.
Their legs alone are about 6ft taller than the average human. Most of their life is spent standing up, they even sleep and give birth standing up. Being as they are so large, the average giraffe weighs 1900kg (4200lbs). They eat over 45kg (100lbs) of leaves and twigs every day.