Cnemidophorus velox is a species of lizard that is native to the southwestern United States and parts of Mexico. The common name for this lizard is the swift or plateau striped whiptail. However, there are several synonyms for this species of lizard. Some of the synonyms include Aspidoscelis velox, Cnemidophorus inornatus, Cnemidophorus sexlineatus, and Cnemidophorus tigris. These synonyms were used before Cnemidophorus velox became the accepted name for this species of lizard. Regardless of the name used, the swift whiptail is a fascinating lizard that is known for its impressive speed and agility.