I'm sure it is not a surprise to learn that these are also called the screwhorn antelope. This is one of the weird cases like the Gooty Sapphire Tarantula I painted. They are very rare in the wild, but are not uncommon in captivity. The Addax is limited to a part of the Sahara now, but in captivity is even used in canned trophy hunts. In 2016 a survey only found 3 in the wild, so it is quite possible they are gone. They live up to 25 years though so hopefully there are some. With 2000 or so in captivity, rather than just hunting them to put them on the wall, maybe they could begin to reintroduce some into the wild.
I don't remember seeing any of these when I went to the wildlife safari (not the hunting kind) in Winston, Oregon.
We did get to see this, which is I believe, one of the fallow deer they have there. They have a Leucistic (white, but not albino) male there too, but I prefer this colouring. I love their big whiskery noses. The Jersey is my favourite kind of cown, and their face is much like these. I've always said the Jersey makes me think of an obese deer.