The Black-tailed Prairie Dog (Cynomys ludovicianus), is a rodent of the family sciuridae found in the Great Plains of North America from about the USA-Canada border to the USA-Mexico border. Unlike some other prairie dogs, these animals do not truly hibernate. The Black-tailed Prairie Dog can be seen aboveground in midwinter. There is a report of a Black-tailed prairie dog town in Texas that covered 64,000 km² (25,000 sq mi) and included 400,000,000 individuals. Prior to habitat destruction, this species was probably the most abundant prairie dog in central North America. This species was one of two described by the Lewis and Clark Expedition in the journals and diaries of their expedition.

Black-tailed Prairie Dogs are generally tan in color, with a lighter colored belly. Their tail has a black tip on it, which is where their name is derived from. Adults can weigh from 1.5 to 3 lb, males are typically heavier than females. Body length is normally from 11 to 13 inches, with a 3 to 4 inch tail. They have small ears, but keen hearing, and small, dark eyes, with good vision.