Cormac is a rail forklift truck who helps Old Puffer Pete at the drop and load freight yard.
Cormac is very cheeky chugger who enjoys pulling small practical jokes on the chuggers but he never takes his jokes too far and always tells the chugger if he has played a practical joke as well. He is very supportive and always works hard to complete his work, even if he does have to have a break every so often.
In his first appearance, he helped Brewster take the last section of the Tootington Tunnel to the worksite. The load was very wide so they had to use two flatbeds and work side by side. However, Cormac got tired and as they went round a bend, then tunnel section fell off and rolled down the hill. Brewster and Cormac had to chase it and then catch it just at the right moment. Then they happily took the tunnel section to the worksite and the tunnel was complete. He was present during the Iron Chuggers contest and set up the wagons with the weight that Speedy and Zack wanted.