Fergus along with Daisy and Dart were some of the newest additions to the fleet in the beginning of Inheritance. Fergus is someone who plays by the rules and always trys to "Do it right" and is not very familiar in the art of troublemaking. When he first arrived Ben attempted to mold him into a someone he wasn't in an attempt to replace Bill. Fergus tried his best but never really succeeded even though he believed he did. After several failed attempts Ben finally gave up and told Fergus that he could never be a troublemaker. This left Fergus feeling defeated, later on Fergus was sent to the transfer yards and found out that he could not leave until an engine whistle was heard. Peter Sam then tells Fergus that he had seen other engines go through the tunnel without the whistle to verify they could leave. Fergus is hesitant at first but then realizes he can prove to ben he is in fact "Bad to the Bone." while doing so he bumps into a fuel wagon blocking the tunnel right in front of a three way intersection. Disaster would soon follow as Paxton accidently shunts some coal truck into the wagon causing a crash. At that very moment scruff comes from the other line and crashes into the wreckage. Ben watches in horror as BoCo trundles next to him. Ben says that he did not teach Fergus that, then at that very moment an explosion occurs.
- Fergus is the first steam engine purchased for the NWR after the events of Season 2.
- Fergus was portrayed using an ERTL Fergus instead of a Wooden Railway one in the last few episodes of the series.