Diesel 10 is a modified diesel with a claw, which he names "Pinchy". He was one of the main antagonists of the TV Show.
There is a large debate to Diesel 10's existence. He first appeared in Thomas and the Magic Railroad, but T1E2H3 and many other fans do not consider this to be in the same Thomas universe as Awdry's and Allcroft's.
In the universe of the final version of Thomas and the Magic Railroad, Diesel 10 arrived sometime long before 2000 and tried to destroy Lady. He chased her and caused her to crash, but was unsuccessful in catching her. Diesel 10 returned many years later to finish his "unfinished business" while the Fat Controller was on holiday and Mr. Conductor was in charge during his absence. Diesel 10 brought his two minions Splatter and Dodge and was determined to find the magic buffers which led to the magic railroad. He never did find them, but Thomas rescued Lady and brought her to Sodor. Diesel 10 found them and a chase ensued. It was at this moment when Splatter and Dodge stopped serving him out of dislike. Diesel 10 almost caught up with Thomas and Lady, but ran over an unstable viaduct and fell into a barge.
In the universe of the original cut of Thomas and the Magic Railroad, Diesel 10 was a new engine brought to help the engines while the Fat Controller was away in 2000. His goal was apparently to make the lives of the engines miserable, and whilst smashing buffers came across the magic ones. The rest is generally the same as stated above, only PT Boomer landed on him when he chased Thomas and Lady.
Whatever happened, Diesel 10 was on Sodor for some reason in 2005, first clearing up scrap and then tree branches. Thomas and Percy were very scared of him, but when the water tower fell down and the airport, he was the only suitable engine to help. At first, he was not willing to help like usual. However, Thomas convinced him, and Diesel 10 cleared up the mess. In 2008, he appeared to be happy when Thomas was found, and in 2010, he spied on the engines at the Search and Rescue Center, making threats like usual. The following year, the Dieselworks were in bad shape, so Diesel 10 hatched a plan to take over the Steamworks. He used Percy be pretending to be his friend, and was successful in taking over the the steam works. However, The Fat Controller quickly put a stop to the siege, and restored the diesel works after a fire destroyed it. Diesel 10 still hangs around at the diesel works.
For all his appearances, Sodor Workshops' model of Diesel 10 is used. Sodor Workshops updated the model in October 2015.
Diesel 10 is a BR Class 42 Warship with an illegally-added claw.
Diesel 10 is considered the main antagonist of the Thomas and Friends universe.
- A Wretched Day for Henry and James (cameo)
- The Blame Game (cameo)
- Bill and Ben the Brave Brothers of Brendam (cameo)
- Engine Unknown (cameo)
- A Tale of a Small Green Engine (cameo)
- Attack of the Railway Pirates(part 2 only)
- Old Reliable(appears in hallucination)
- The Bridge of Caledonian Doom (cameo)
- Special Engines (cameo)
- Haunted Henry (part 2 only [Henry's dream and surprise scream at the end only])
- How the Diesel Stole Christmas (Diesel's mind only, later destroyed)
- The Most Famous Engine (cameo, Part 2)
He will have a large role in the Engines of Sodor Finale trilogy.
- Great Western Escape (appears in dream, cameo)
Diesel 10 first appeared in Thomas and the Magic Railroad. He then appeared in Calling All Engines, The Great Discovery (cameo), Misty Island Rescue (post credits), and Day of the Diesels. He then made his first (and only so far) TV appearance in the 17th season episode The Missing Christmas Decorations. He is voiced by Matt Wilkinson. He was previously voiced by Neil Crone in Thomas and the Magic Railroad, though was originally going to be voiced by Keith Scott. Also, he was originally voiced by Rupert Degas in Misty Island Rescue but was replaced by Wilkinson for a similar reason why Keith Scott got replaced.