Look at those horns: they can measure more than two meters from tip to tip. This is the Watusi, a breed of cattle from central and eastern Africa, and one of the animals with the most spectacular horns on the planet. For centuries it was the cattle of kings and chiefs. The bigger the horns, the more prestige their owner had. But they are not just for show: inside, they are laced with blood vessels and work as radiators. The blood cools as it passes through them and helps the animal withstand the African heat. And when the herd feels threatened, the adults form a circle with the calves in the middle and their horns pointing outward. An imposing defense for a surprisingly calm animal.