- "This lucky tender engine has a real history with the Great Railway Show, a true hero story to tell: Carlos was the very first winner at the strength competition back at the first ever Great Railway Show!"
- ―The Announcer, Meet the Contenders
Carlos is a small Mexican tender engine who has competed in the Great Railway Show every year since the event's inception. He competed in the best decorated parade.
Carlos first participated in the very first Great Railway Show, competing in the strength competition. He ended up winning this event.
Carlos continued to compete in the Great Railway Show every year. When the show was being held in England, he competed in the best decorated parade. He competed against Yong Bao, Rajiv, James and Emily, but ended up losing the event to Rajiv. Later, as he was refilling his tender with coal, Carlos was forced to reverse when Philip was trying to escape from Vinnie, causing the latter to be covered in coal dust when the hopper was still pouring coal out.
After the Great Railway Show ended, Carlos left the Mainland and returned to Mexico.
Carlos is a proud and happy steam engine from the heart of Mexico. Always wearing a smile, this engine is the life and soul of the Great Railway Show. Originally competing and winning the strongest engine race at the very first Great Railway Show, this engine continues to please the crowds and is now taking part in the Best Decorated Engine Parade.
Carlos is based on the Ferrocarriles Nacionales de México (National Railways of Mexico) GR-3 class 2-8-0, built by the Baldwin Locomotive Works of Eddystone, Pennsylvania. The engine bearing his number, 903, was built in 1910 and was originally built for narrow gauge tracks and was used by the Veracruz Terminal Company and the Teziutlan Copper Company before being bought by NdeM in 1945. Re-gauged to standard gauge in 1950 and taken out of service in 1963, the engine is currently on display outside the José Cardoso Tellez Railway Museum in Acámbaro in the Mexican state of Guanajuato.
Carlos is painted black with a silver smokebox, cowcatcher and bell. His cab doors, windows, handrails and other details are painted red, while his sandboxes and dome are painted with green lining around them. He carries his number on both his headlamp and cab, and the initials "N. DE M." are painted on each side of his tender.
- 2016 - The Great Race (not named)
- James the Really Splendid Engine (CGI version)
- Guess Who? Puzzles (does not speak)
- 2016 - Meet the Contenders: Carlos of Mexico (does not speak)
- 2017 - Great Race Friends Near and Far: Carlos Races Raul!
- David Bedella (UK/US)
- Junichi Kanemaru (Japan)
- Roberto Mendiola (Latin America)
- Joachim Kretzer (Germany)
- Despite competing in the Best Decorated Engine Parade, Carlos is not decorated or repainted for the event, whereas the other four competitors for the challenge are.
- Carlos has been partially modified to work on British railways, he has added buffers. His lamp has also been moved to accommodate his face. As such, his bell has been moved to accommodate his lamp.
- When Carlos backs away from the coal hopper, he says the phrase "Fizzling fuegos!", where in Spanish, "fuegos" means fires.
- Carlos' whistle is the same as Ferdinand's, but at a normal pitch just like the Rainbow Sun's.
- According to the behind the scenes video of The Great Race, Carlos was originally going to be an NdeM NR-1 class 4-6-4 Hudson locomotive.
- Like Hiro and Yong Bao, Carlos has a knuckle coupler on his front and a chain and hook coupler on the back of his tender.
- Despite Carlos burning coal, his basis is an oil burner.
- "Fizzling fuegos!"
- Carlos gasping in horror when he saw Philip coming towards him, The Great Race