Velociraptor, whose name means "swift thief," is a genus of dromaeosaurid theropod dinosaur that lived during the Campanian period, toward the end of the Cretaceous Period, about 75 to 71 million years ago, in what is now Asia.

Although smaller than other dromaeosaurids, Velociraptor had many anatomical features similar to them.

It was a bipedal carnivore, with a long, stiff tail and large, sickle-shaped claws on each foot, which probably made it easier to kill its prey.

Velociraptor, like other dromaeosaurids, had three curved claws on each hand and long phalanges, with bones similar in shape and flexibility to the wing bones of modern birds. The first of these three phalanges was the shortest, the second being the longest. The structure of the carpal bones prevented pronation of the wrist and forced the claws to face upward.

Unlike most theropods, which had three functional toes on each hind limb, dromaeosaurids like Velociraptor walked only on their third and fourth toes. The first toe, like other theropods, was a small, vestigial claw, separate from the others and without any function. The second toe, to which Velociraptor owes part of its fame, was highly modified and remained retracted, not touching the ground. It bore a huge sickle-shaped claw, typical of dromaeosaurid and troodontid dinosaurs. This elongated claw, about 65 millimeters long along its outer edge, was capable of inflicting fatal wounds.

The kicking muscles of the leg and the toe flexors were well developed and enabled the claw to function like a deadly switchblade. It has conventionally been believed that this animal stood on one hind leg and launched an attack with the other; its tail would have functioned as a seesaw.

Velociraptor had a low, elongated skull and a flat, upward-pointing snout. It had very long hind legs, reflecting its apparent great speed.

Velociraptor's tail was rigid, with long bony projections at the top of each vertebra and ossified tendons beneath it. These bony projections began at the tenth caudal vertebra and extended forward to reinforce four to ten additional vertebrae, depending on the position of the tail. This rigidity reinforced the entire tail, allowing it to act as a bar-like unit, preventing vertical movement between the vertebrae. However, at least one specimen preserves a series of intact caudal vertebrae in an S-shaped curve, suggesting considerable horizontal flexibility. These tail adaptations likely provide balance and stability when turning, especially at high speeds.