|First Appearance||Branch Line Bother|
|Voiced By||Open for audition.|
Proteus was an engine who once worked on the Mid Sodor Railway.
Proteus was built at Falcon Works in Loughborough along with Falcon and Sir Haydn. Proteus was purchaced by the Mid Sodor Railway in 1902.
Bertram teased Proteus about his lamp, saying it was lucky. Proteus didn't believe him and dismissed his remark.
Proteus was called in to finish the gunpowder train's journey, as Smudger had derailed as usual. During the journey, his lamp had broken unexpectedly. He couldn't see the branch on the line ahead of him, but when he did, the sparks set the gunpowder wagons on fire. Smudger returned to collect the charred remains of Proteus, and some say his specter still roams the Arlesdale railway to this day.
Proteus is good natured, play-by-the-rules kind of engine. He has no sense of humor and is bothered by Bertram's constant Shakespearean ways, much like Duke.