Flightless birds with similar characteristics to the ostrich, Phorusrhacids could reach land speeds comparable to cheetahs.
Up to 1,000 pounds (454 kg) and 9 feet (3 m) tall, these creatures could easily grasp a medium-sized dog in a single bite (and their hooked bill allowed them to tear into larger animals as well.) They really deserve their nickname, the “terror bird”.