The pacarana (Dinomys branickii) is a rare and slow-moving hystricognath rodent indigenous to South America.

The pacarana has a chunky body and is large for a rodent, weighing up to 15 kg (33 lb) and measuring up to 79 cm (2 ft 7 in) in length, not including the thick, furry tail.

[2][3] The pacarana is nocturnal and is found only in tropical forests of the western Amazon River basin and adjacent foothills of the Andes Mountains.

It ranges from northwestern Venezuela and Colombia to western Bolivia, including the Yungas.

Initially, the pacarana was regarded as a member of the superfamily Muroidea, that includes the true mice, but that view was abandoned in the face of evidence that suggests that the pacarana is in the family Dinomyidae together with extinct animals such as Phoberomys pattersoni and Josephoartigasia monesi, prehistoric giant rodents that lived in South America several million years ago.