Maybe a kangaroo will do, if our tiger cub doesn't bite too much. Habitat loss causes most extinctions today. Ranchers converted thylacine habitat into rangeland for livestock. Livestock interests continue blocking efforts to reintroduce wolves, grizzlies, and bison in western North America. Considerable ground for wildlife could be gained if we pulled the subsidies feed bag from grazers, and stopped buying their meat and by-products, but until we restore habitat on a large scale, even wildlife that doesn't have to be brought back from the dead has no home.
Contraception is cheaper.
We aren't domesticated enough to keep from going bonkers in remote, desolate outposts like Antarctica. To seriously imagine ourselves living that way reveals the extent of our disconnect from Nature. We barely live healthy lives in our artificial environments here on Earth. Indoor air averages many times more toxic than outside air. Although our cage bars may only be abstract, like the bars crossing the E, S, L, and Y in money, their specter crosses our paths to freedom.