- 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 first participated in the Great Railway Show during the very first event, 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. 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 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.
- The Great Race (not named)
- Meet the Contenders: Carlos of Mexico (does not speak)