Say hello to the gelada. Theropithecus gelada (theropithicus = "beast-ape") is a baboon relative native to Ethiopia, though the fossil record has them all over northern Africa and even into Spain.
What impresses me most about this monkey, aside from the mane on the males, is that hour-glass patch of bright skin that looks as though the animal's chest and neck is being flayed open.
The patch is prominent in the males, less so in the females. But, when the female is in oestrus, the patch brightens and even becomes festooned with a 'necklace' of fluid-filled blisters.