5. Northern White Rhino
We've been talking so far about species with populations in the dwindling hundreds. There are currently only three northern white rhino left on the planet. Three. They have been poached to almost total extinction, and actual total extinction in the wild, for their horns. Totally uncontrolled hunting during the colonial era started them on their nosedive and now modern poaching is well and truly finishing them off. The horn is powdered and used in traditional ancient medicine (which, by the way, has absolutely no effect) and has also seen a recent surge in popularity with the Vietnamese upper middle class, who consume it purely as a symbol of wealth and status. If we can't get the animals that we have in captivity to mate and reproduce, this could be it for the northern white rhino.