Fergus is a small railway traction engine who works at the Sodor Cement Works.
Fergus is a small railway traction engine whose main function is to shunt trucks at the Cement Works. It's dusty work and has left him with a slight but persistent cough, which punctuates his speech. Fergus believes in playing by the rules and is resistant to change. 
Fergus mainly works at the cement works. Fergus knows the rulebook off by heart, and his catchphrase is "Do it right!" His insistence on doing everything absolutely according to the rules can annoy the other engines, but he is a decent engine at heart and will not hesitate to help others in trouble.
He is known to be a strict engine, knowing every rule and regulation by heart, and is constantly nagging the other engines to “Do It Right!” if they ever did wrong. But he is a kind engine as well, and prefers working with sensible engines who complete their jobs without fuss.
Fergus is based on the Aveling and Porter 2-2-0 'T9' class railway traction engine No. 9449 "Blue Circle", which is the only one left in the world. Since Fergus' introduction, "Blue Circle" has been dressed up as Fergus on special occasions on its home line, the Battlefield Line in Leicestershire.
- Tom Kenny (UK/US; coming soon)
- He has a flywheel which can be used to power tools, such as a saw, drill or pump. It has also powered a generator in the past.
- Fergus has never been seen with a fireman, only a driver.