Cormac is the resident joker of the Celgreb City Freight Depot. Equipped with his handy-dandy forklift arm and a useful trailer-wagon, Cormac keeps busy helping Old Puffer Pete and Rosie out by lifting, loading, and shunting truckloads of containers into place. Cormac is a known prankster, but his jokes aren't out of spite or meant to harm anyone; they're meant out of good intentions and a need to keep high spirits in the busy freight yards!
Cormac seems to be of a freelance design and isn't based on a specific prototype.
Cormac is viridian with some thick yellow stripes. His bottom jaw, buffer beams and cab roof is yellow too and he has an orange siren light.
- Christopher O'Shea suggested a Railside Tales episode where Cormac got to work with Bill and Ben. It is unknown whether or not it will actually be made.
- In the original script of Meet The Crotoonians: Tillie And The Troublesome Trucks, he was going to be one of the main characters. However, his model wasn't built in time, so he was replaced with Old Puffer Pete instead. A mention of him was recorded during production of the episode, but was snipped out to leave just Rosie (who'd been finished) instead.