Hippos do not sweat blood, but it’s an understandable misconception based on a glandular condition of the Nile hippo.
This aquatic beast has a mucous gland that, when its owner is startled, nervous, or excited, produces an oozing, reddish-tinted liquid that’s easily mistaken for blood.
The oily liquid normally helps keep the hippo’s skin from getting cracked and dry in the hot sun, but the gland’s sudden excretions may also serve to scare off potential predators.
