Doc is the doctor engine in the 1991 film, The Little Engine That Could.
An old, experienced steamer, Doc is usually first to arrive at an emergency after the Crotoonian Rescue Squad/Patrol arrives. He'll usually examine the engine, and give them their diagnosis, along with assisting as much as he can. Doc is wise, experienced, and ready for any kind of emergency on the rails. He resides at the Kahville Works with Mary the Works Diesel, Kevin and Victor.
Doc is of a freelance design. He doesn't seem to be based on a specific prototype.
- Doc originated from the 1991 'The Little Engine That Could' movie. Other engines from the film include Big Freighter Pete, Farnsworth, Georgia, Jebediah and Tillie.