Fergus is a railway traction engine.
Fergus mainly works at the cement works and is thus called "the pride of the cement works". According to The Official Website, Fergus now has a slight but persistent cough which affects his speech, caused by working at the dusty 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.
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.
Fergus is painted royal blue with gold boiler bands and red wheels.
- 2004 - Fergus' Funnel, Snake's Alive!, Rock Shock!, and Salty by the Sea (cameo)
- 2005 - Working Christmas (cameo)
- 2007 - Fly Along, Fergus! and Bridge Bother (mentioned)
- 2008 - Fast and First! and Left Alone (does not speak)
- 2011 - Slowcoach Diesel
- Ryōtarō Okiayu (Japan)
- According to the official website, Fergus' flywheel 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.
- In a SiF interview with Chris Lloyd, it was mentioned that Fergus' model was damaged during the filming of Bill, Ben and Fergus. His model still worked, but the flywheel couldn't turn anymore, nor could he puff steam. This may be why he never appeared after the seventh season.
- Fergus differs slightly from his basis: his smoke box is larger to accommodate a face. His bufferbeam is also missing a large section for the same reason.
- According to Robert Gauld-Galliers's concept art, Fergus was originally going to have oval shaped buffers.
- Fergus incorrectly has black buffers on many of his promotional artwork.