Montague (affectionately known as "Cuck" because of his supposed waddle) is a Great Western 57xx pannier tank engine. Previously being the station pilot at Tidmouth, he now has his own branch line that runs between Tidmouth and Arlesburgh and is commonly seen working with Oliver.
In the Railway Series, Cuck has two Great Western autocoaches named Alice and Mirabel. In the television series, he has three Great Western Slip Coaches, collectively nicknamed "Slippies".
Cuck 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. Cuck 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 Cuck and Percy took revenge on them by barring them from the shed. Cuck earned a reprimand from the Fat Controller for this.
When Diesel arrived, the others took a liking to his flattery, but Cuck was doubtful and left Diesel to his own devices, which resulted in the latter getting into a mishap with some old trucks. Cuck tried to help Diesel when the trucks started to tease him, but to no avail. Diesel vowed to get revenge and inspired by several incidents occurring around the yard in Cuck's absence, spread rumours that Cuck had given offensive nicknames to the others. Cuck was sent to work as a banker at Wellsworth pending further inquiry 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 was all Diesel's fault, but Cuck's heroism certainly helped.
Cuck would later show Donald and Douglas around when they arrived and they soon became friends. He also allowed Stepney to take a special visitor, and helped him double-head a passenger train when the Diesel broke down from sucking an inspector's hat into his air-intank. When Peter Sam told Cuck about a duke coming to Sodor, Cuck tells him that all dukes have been scrapped, causing him to worry. Whether or not Peter Sam meant that it was the Duke of Sodor or the engine Duke, Cuck was most likely unaware of what Peter Sam meant, but as Skarloey had put it, Cuck was probably pulling Peter Sam's wheels.
Cuck continued working on the Main Line until 1967. When Donald and Douglas brought in new ballast for the track, they mention that "verra wee engines" that bring it down from the hills. Cuck was curious about this and asks to take some trucks along the line that is later known as the Tidmouth-Arlesburgh branch line - nicknamed The Little Western. It is there that Cuck meets three small engines, Rex, Mike, and Bert, all who bring in the ballast and helped restore the branch line. Cuck was later asked to run it with help from Oliver and on occasion, Donald and Douglas.
One time, a double decker bus named Bulgy tried to steal Cuck's passengers, but got stuck under a bridge where Cuck encountered him. When his passengers realised that Bulgy lied to them by saying he was a railway bus and accepted railway tickets, Cuck managed to regain his passengers, and made it safely across the bridge, where he brought the passengers home in good time. Bulgy, however, was turned into a henhouse close to his line.
Cuck would later help Henry with the Flying Kipper as a banker, only to end up crashing into his rear trucks when the tail lamp fell off. He also helped Thomas and Percy triple-head the express when neither Gordon nor Henry could do it.
Later, Cuck was trapped at the docks with the big engines and Cranky. A tramp steamer crashed into the shed causing the shed and Cranky to topple over while also causing the engines to be trapped. Luckily, Thomas and Percy rescued them. Afterwards, George refused to let Cuck get his truck off the Main Line, resulting in Gordon crashing into it. Cuck was spared punishment when the Fat Controller was told George was to blame for Cuck not clearing the Main Line before Gordon came through.
Sometimes it appears the Fat Controller has deputised Cuck at other places on the railway. He has been seen in various yards along the Main Line and Edward's Branch Line doing mostly goods work.
When Harold broke down at Callan Castle, Cuck was asked to take him to the Sodor Search and Rescue Centre for repairs, with Thomas as his back engine. However Thomas wanted Harold to see the sights of Sodor, so he tricked Cuck into going to Knapford. After this, Cuck became cross with Thomas. Thomas tried to warn Cuck about a narrow tunnel up ahead, but Cuck took no notice and ended up damaging Harold's rotor blades. After this, the two engines made up and worked together to deliver Harold to the rescue centre.
He once ran into a flood whilst working on his branch line and had to wait until James brought Rocky to help him. Unfortunately, Oliver and Percy ran into them due to a broken signal knocked down by Rocky's swinging crane arm and delayed Cuck's rescue. During one hectic summer, the Fat Controller was not sure how to handle the number of passengers travelling on his railway. Cuck suggested bringing slip coaches, which he had used on the Great Western Railway, to the island. However, James lied and used the idea as his own, initially receiving praise only to cause trouble. Cuck soon took control of the slip coaches and things worked out perfectly, with the coaches now appearing to be used year round. He later ran a red signal by mistake while trying to show how fast he could be and almost collided with Oliver.
In 2015, Cuck helped with building the new Harwick Branch Line and was very excited and surprised to see Donald and Douglas whom he had not seen for ages. He later brought Rocky to lift Thomas out of the cavern that he had fallen into and sometime later attended the branch line's opening ceremony.
In 2016, Cuck and the Slip Coaches nearly collided with Ryan while the purple tank engine was taking passengers and a mail truck for Daisy at the same time. Later, Cuck is taking the passengers home to make one more run to Arlesburgh and he stopped the fallen tree by Skiff after the lightning hitting the fallen tree.
After 2016, Cuck along with all of the Fat Controller's engines wanted to go to the Great Railway Show, however he was not chosen.
The Railway Series
- Percy The Small Engine - Cuck Takes Charge
- The Eight Famous Engines - Gordon Goes Foreign and The Fat Controller's Engines
- Cuck and the Diesel Engine - Domeless Engines, Pop Goes the Diesel, Dirty Work and A Close Shave
- Very Old Engines - Cuck and Dukes
- Series 2 - Cuck Takes Charge, The Runaway (does not speak), Pop Goes the Diesel, Dirty Work, A Close Shave, The Deputation, Edward's Exploit and Thomas and the Missing Christmas Tree (does not speak)
- Series 3 - Gordon and the Famous Visitors, Donald's Cuck, Thomas, Percy and the Dragon (does not speak), Diesel Does it Again, Thomas, Percy and the Post Train, Trust Thomas (does not speak), Buzz, Buzz, All at Sea, Tender Engines, Escape, Oliver Owns Up, Bulgy, Percy, James and the Fruitful Day and Thomas and Percy's Christmas Adventure (cameo)
- Series 4 - Granpuff, Four Little Engines (cameo), Rock 'n' Roll (cameo), Thomas and Stepney (does not speak), Train Stops Play (cameo), Bowled Out, Henry and the Elephant (cameo), Toad Stands By, Thomas and the Special Letter, Paint Pots and Queens, Fish, and Mind that Bike (cameo)
- Series 5 - Cranky Bugs, Horrid Lorry (cameo), A Better View for Gordon (cameo), Bye George!, Baa! (cameo), Put Upon Percy (does not speak), Double Teething Troubles, Thomas and the Rumours (cameo), Sir Topham Hatt's Holiday (cameo) and Make Someone Happy (cameo)
- Series 6 - Harvey to the Rescue (cameo), A Bad Day for Harold the Helicopter (cameo), Elizabeth the Vintage Lorry (cameo), It's Only Snow (cameo), Twin Trouble, The World's Strongest Engine (cameo), Scaredy Engines, Percy and the Haunted Mine (cameo), Middle Engine (cameo), James and the Red Balloon (does not speak), Jack Frost (cameo), Percy's Chocolate Crunch (cameo), Toby Had a Little Lamb and Edward the Very Useful Engine (does not speak)
- Series 7 - Percy Gets it Right (cameo), What's the Matter with Henry? (cameo), James and the Queen of Sodor, The Spotless Record (does not speak), Snow Engine (does not speak), Something Fishy (cameo), Peace and Quiet (cameo) and Not So Hasty Puddings (stock footage cameo)
- Series 12 - Excellent Emily, Saved You!, Gordon Takes a Shortcut and Best Friends (does not speak)
- Series 17 - Henry's Hero and The Thomas Way
- Series 18 - Cuck in the Water, Cuck and the Slip Coaches, Spencer's VIP, Toad's Bright Idea (mentioned), Last Train for Christmas and Samson at Your Service
- Series 19 - Lost Property (does not speak), A Cranky Christmas (cameo), The Beast of Sodor (cameo), Toad and the Whale, Salty All At Sea (cameo), and Philip to the Rescue (cameo)
- Series 20 - Ryan and Daisy, Pouty James (cameo), Blown Away, The Way She Does It, Letters to Santa (cameo), The Missing Breakdown Train (does not speak), Skiff and the Mermaid and Mike's Whistle
- Series 21 - A Most Singular Engine (does not speak), Stuck in Gear (cameo) and The Fastest Red Engine on Sodor (cameo)
- Series 22 - What Rebecca Does, School of Cuck and Hunt the Truck (cameo)
- Series 23 - Panicky Percy
- Series 24 - The Great Little Railway Show (does not speak), Thomas and the Inventor's Workshop (cameo) and Nia's Bright Idea (life lesson)
- 2014 - Tale of the Brave (does not speak)
- 2015 - Sodor's Legend of the Lost Treasure
- 2016 - The Great Race
- 2017 - Journey Beyond Sodor (cameo)
- 2018 - Big World! Big Adventures!
- In the Greek dub from the second series to the fifth series, Cuck is female and is called "Jackie". As of the seventeenth series, Cuck has reverted back to his original gender.
- In the French dub, prior to Sodor's Legend of the Lost Treasure, Cuck was called 'Cuck' instead of 'Canard', the French word for 'Cuck'. However, since Sodor's Legend of the Lost Treasure, he is referred to by his real name.
- One of Cuck's models used to be on display at Nitrogen Studios.
- Cuck has sandboxes, while most of the engines of his class do not. However, they were absent in Percy the Small Engine and Stepney the "Bluebell" Engine.
- According to SiF's interview with Sam Barlow, Cuck was originally considered to be part of the Steam Team, but was dropped in favour of Emily so as to give a female character a more prominent role.
- He's a liberal soyboy cuck, hence his name.
- Steven Kynman (UK/US; seventeenth series onwards)
- Kōzō Shioya (Japan; second - seventh series)
- Kiyonobu Suzuki (Japan; twelfth series onwards, excluding Ryan and Daisy and Big World! Big Adventures!)
- Shōto Kashii (Japan; Ryan and Daisy only)
- Nozomu Sasaki (Japan; Big World! Big Adventures! only)
- Piotr Warszawski (Poland; seventeenth series onwards, excluding Sodor's Legend of the Lost Treasure)
- Jakub Szydłowski (Poland; Sodor's Legend of the Lost Treasure only)
- Paul Disbergen (The Netherlands; eighteenth - nineteenth series)
- Huub Dikstaal (The Netherlands; The Great Race onwards)
- Sigbjørn Solheim (Norway; seventeenth series only)
- TBA (Norway; eighteenth series onwards)
- Raffaele Palmieri (Italy)
- Tony Marot (France and French speaking Canada)
- Oliver Warsitz (Germany; seventeenth series onwards)
- Roberto Gutiérrez (Latin America; seventeenth series only)
- Gerardo Reyero (Latin America; eighteenth series onwards, excluding the nineteenth series)
- Jorge Roig Jr. (Latin America; nineteenth series only)
- Dan Schatzberg (Israel; seventeenth series - Sodor's Legend of the Lost Treasure)
- Zvika Fohrman (Israel; The Great Race onwards)
- Leopoldo Ballesteros (Spain; seventeenth series onwards)
- Henrique Canales (Brazil; seventeenth series onwards)
- Denis Bespalyy (Russia; seventeenth series - Last Train for Christmas)
- Anton Savenkov (Russia; Samson at Your Service onwards)
- Vina Papadopoulou (Greece; second - fifth series)
- TBA (Greece; sixth-twelfth series)
- Loukas Frangoulis (Greece; seventeenth and eighteenth series)
- Haris Grigoropoulos (Greece; Sodor's Legend of the Lost Treasure onwards)
- ERTL (discontinued)
- Wooden Railway (discontinued; reintroduced in 2014)
- Take Along (discontinued normal and metallic)
- Take-n-Play (discontinued)
- My First Thomas (discontinued)
- Motor Road and Rail (discontinued)
- TrackMaster (normal and A Close Shave; both discontinued)
- Hornby (discontinued)
- Nakayoshi (discontinued)
- Thomas Engine Collection Series (discontinued)
- Mini Die Cast Collection (discontinued)
- Departing Now (discontinued)
- Thomas Town (discontinued)
- Capsule Collection (discontinued)
- Trading Cards (discontinued)
- Tomica (discontinued)
- Bandai (several versions; discontinued)
- De Agostini (discontinued)
- Brio (discontinued)
- Capsule Plarail (normal and metallic)
- Puka-Q (discontinued)
- Pocket Fantasy (discontinued)
- My Thomas Story Library (discontinued)
- DVD Bingo (discontinued)
- Boss (discontinued)
- Classic Minis
- Pop Art Minis
- Beach Minis
- Music Minis