Montague (affectionately known as "Duck" because of his supposed waddle) is a Great Western pannier tank engine.
Duck worked at Paddington before moving to Sodor in 1955 to take over Percy's shunting duties, leaving the latter free to assist with the construction of Knapford Harbour. Duck was a hard worker, but the others mistook his work ethic for simplicity and tried to use this to their advantage. They soon found their mistake when Duck and Percy took revenge on them by barring them from the shed.
When Diesel arrived, the others took a liking to his flattery, but Duck was doubtful and left Diesel to his own devices, which resulted in the latter getting into a mishap with some old trucks. Diesel vowed to get revenge and, inspired by several incidents occurring around the yard in Duck's absence, spread rumours that Duck had given offensive nicknames to the others. Duck was sent to work as a banker at Wellsworth pending further injury and after bravely stopping a runaway goods train at his own risk regained the respect of the others. Of course, by this time the others were aware that the matter of all Diesel's fault, but Duck's triumph certainly helped.
Duck continued working on the main line until 1968, at which time the Tidmouth-Arlesburgh branch line - nicknamed The Little Western - was restored and Duck was asked to run it with help from Oliver and, on occasion, Donald and Douglas.
- Duck is also best friends with Braeburn.
- Duck is Princess Celestia's boyfriend and later husband (in Iamnater's series).
- Tigger refers to him as "Ducky boy".
- Duck will join Thomas and Twilight Sparkle's Adventures Team in
- Duck will appear again in Brian Griffin's Adventures of Transformers: Age of Extinction and Brian Griffin vs. The Mummy: Tomb of the Dragon Emperor.