Przewalski's horses (© Nemyrivskyi Viacheslav/Getty Images)

This species missed the domestication memo and kept going on its own terms. Say hello to Przewalski's horse, considered the last truly wild horse on Earth. Once widespread across Central Asia, it disappeared from the wild in the 1960s after decades of hunting, habitat loss and competition with livestock. Its survival depended on an unlikely lifeline: a small number of individuals captured by early 20th‑century collectors, which became the foundation of all modern Przewalski's horses.