DRDs, short for Diagnostic Repair Drones, are mechanical devices that work on Leviathan ships. There are thousands of DRDs on Moya, each with its own set of tasks to perform.

When Crichton was left on his own in the fourth season episode "Crichton Kicks", he relieved his boredom by adopting one of the DRDs as a pet. He painted it red, white and blue, and taught it to play Tchaikovsky's "1812 Overture"; he named the DRD 1812.