Deinonychus was a slender, fast-moving, agile, bipedal, bird-like dinosaur. It was built for killing.
This carnivore had a bent, flexible neck and a large head with sharp teeth in very strong jaws. Each of its three fingers on each hand had a large, sharp, curved claw.
His long tail had bony ridges along the spine, which gave him a hardness, and he also used his tail for balance and quick turns. Deinonich had a relatively large brain and large, sharp eyes.