Pituophis catenifer is a species of nonvenomous colubrid snake endemic to North America. Nine subspecies are currently recognized, including the nominotypical subspecies, Pituophis catenifer catenifer, described here. This snake is often mistaken for the prairie rattlesnake, but can be easily distinguished from a rattlesnake by the lack of black and white banding on its tail and by the shape of its head, which is narrower than a rattlesnake's.

Colubridae is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. Colubrid snakes are found on every continent except Antarctica.