Dumb Muscle: Downplayed. Den is the bigger and stronger one of the two, but struggles to get his thoughts into words. Cinema Set ( includes playmat with Thomas, Percy, Oliver, Diesel 10, Hiro, Belle, Flynn, Den, Harold and Sir Topham Hatt) ( discontinued) Too Fast to Stop: What ultimately defeats him in Thomas And The Magic Railroad. While Diesel 10 is faster and stronger than both Thomas and Lady, they're small enough to cross the collapsing viaduct while he can't due to his bigger size and weight. This also means he's unable to slow down in time to avoid falling. Visible Invisibility: Merlin believes he can turn himself invisible, but in actuality, it all turns out to be the effects of smoke and reflective silver paint. Lexi and Theo are nice enough not to tell him that he isn't really invisible.

Soon the steam and diesel engines work together to restore the Dieselworks. At the opening, the Fat Controller says that the new Dieselworks is special because it shows what happens when Really Useful Engines work together and that he is very proud of all of his engines. Percy rolls up beside Thomas and tells him that he feels proud and special when he is with him and Thomas says the same thing. The two best friends laugh together. Asshole Victim: Yea, Annie and Claribel made rude remarks towards her in "The Railcar and the Coaches". However, she's also a snob who bullied them and didn't even try to apologize.Feeling Their Age: Starts to worry he might be getting old when he starts making terrible creaking sounds. Completely gets over it when the new crane, Carly, makes the same creaks on her first day. Sodor's Legend of the Lost Treasure was the first special not to have any play-sets that was associated with the film. Annie and Clarabel | Henrietta | Alice and Mirabel | Isabel and Dulcie | Victoria | Old Slow Coach | Slip Coaches | Hannah | Dexter | Express Coaches | Branch Line Coaches | Old Coaches | Thomas' Special Coach | Emily's Coaches | Toby's Museum Coach | Flora's Tram Coach | Open-Topped Carriages | Ulfstead Castle Coaches Kindhearted Simpleton: He's not exactly the smartest engine in the shed, but he is one of the nicest engines on the island, even when he is up on a hoist.

The prototypes of Emily, Molly and the Big City Engine had six wheels on their tenders, while their final models have four. After the narrator says, "And into the shadow of Diesel 10," for a split second as the scene fades in, the scene is frozen. Cheated Angle: In the model series, his nose is tilted more towards his left eye. This was averted when the CGI series came, which moved it more to the middle of his face. Feeling Their Age: In King of the Railway, he spends a day trying to prove himself useful to the railway. Being unable to handle essentially any task he's given hits him hard.The first special not to have Togo Igawa as part of the voice cast since he joined the voice cast since the CGI switch. Affably Evil: By the time of Day of the Diesels where his evil ways are mostly put on the wayside in favor of him being rude and vicious-tempered, but just trying to look out for his diesel brethren, whom he sees as neglected.

The first time a driver has a speaking role since the tenth series episode, It's Good to be Gordon. Calling All Engines! | The Great Discovery | Cancelled 2009 Special | Hero of the Rails | Misty Island Rescue | Day of the Diesels | Blue Mountain Mystery | King of the Railway | Tale of the Brave | The Adventure Begins | Sodor's Legend of the Lost Treasure | The Great Race | Journey Beyond Sodor | Big World! Big Adventures! Jerkass Has a Point: In "The Railcar and the Coaches", Daisy substitutes for Thomas on his branch line while Thomas has to work at the quarry. Daisy is rude to Annie and Clarabel, Thomas' coaches, at one point saying that as a diesel railcar, she can go wherever she wants whenever she wants, whereas they are coaches, who can't move by themselves and have to wait for an engine to pull them. While Annie and Clarabel are offended by what Daisy said about them, they do realize she's right about it. Devil in Plain Sight: The steam engines all can tell he's clearly evil, but the Fat Controller keeps him around for reasons unknown. Downplayed in the series, where he is still a devious schemer, but his attitude leans more towards Jerkass/ Jerk with a Heart of Gold than than just outright evil. The original Talking Diesel and the redesigned UK versions from 2014-2015 have his horn sound from Misty Island Rescue to the fourteenth series, except the redesigned US versions from 2014 and 2015 who have his original horn sound.Timothy, 'Arry, Bert and the post-2013 re-designed models of Diesel, Paxton and Sidney all have side rods moulded onto their sides. Series 21 - Springtime for Diesel, Dowager Hatt's Busy Day ( cameo), The Big Freeze and Daisy's Perfect Christmas Expy: He shares similarities with Skarloey: Old red colored engines with the #1 and share the same voice. Token Good Teammate: Like Paxton and the other friendly diesels, he serves as one of the nicer ones.