- “I get dirty! I need washdowns, Gordon only does it to feel important!"
"I am important, I'm an express engine."
"You're a pouty puffer Percy."
"No I'm not!”
- ―Percy, Gordon and James
Percy's Chocolate Crunch is the eighteenth episode of the sixth series.
Percy has been frequently working the dirty jobs involving trucks and longs for a washdown as much as any engine. Unfortunately, when he goes to the washdown, Percy and the other engines are informed by Sir Topham Hatt that, due to a water shortage, all engines can only have one wash per day and that usefulness comes before cleanliness. This irritates Percy as he thinks that Gordon only needs a washdown to feel important. Gordon points that he is important as he pulls the express. James teases Percy, who does not see the funny side before going back to work.
Percy returns to work at the coaling plant, determined not to get dirty. But the trucks are up to their old tricks, and pull Percy right under the coal hopper, and coal pours on top of him. On their way to Callan, the trucks tease Percy by singing a rude song to him. Percy hates it when they make fun of him, so he angrilly tells them to stop it.
Once at Callan, Percy shunts the coal cars into a siding, right alongside Harold who is unloading medical supplies. Harold takes off, spreading cinders and ashes all over Percy, who demands for a washdown, but his driver reminds him that usefulness comes before cleanliness, but Percy wants a clean job more than anything. The driver suggests taking vans of sugar to the chocolate factory, so Percy takes the vans of sugar, feeling happy.
Percy, thinking that he finally has a clean job, is unaware that a patch of oil had been caused by a leakage from a frieght car in the siding at the chocolate factory. Upon arrival, the brakes are applied but Percy slips on the oily rails and crashes through the wall right into the chocolate factory, across the factory and out the other end, covered in chocolate.
When Duck brings Percy back to Tidmouth Sheds, Thomas, James, and Henry tease him saying how chocolatey he is, but Gordon disapproves. Sir Topham Hatt knows how much work Percy had done despite his problems and the accident; and as he proved that usefulness comes before cleanliness, Percy is rewarded with a washdown and a new coat of paint which makes Percy happy.
- Sir Topham Hatt
- Edward (cameo)
- Toby (cameo)
- Duck (cameo)
- Oliver (cameo)
- Annie and Clarabel (cameo)
- Henrietta (cameo)
- Mrs. Kyndley (cameo)
- Jem Cole (cameo)
- Farmer Trotter (cameo)
- Nancy (cameo)
- The Storyteller (cameo)
- The Lighthouse Keeper (cameo)
- The Fisherman (cameo)
- Mr. Jolly (factory logo only; mentioned)
- Mavis (deleted scene cameo)
- Tidmouth Sheds
- Tidmouth Bay
- Gordon's Hill
- The Coaling Plant
- The Viaduct
- The Windmill
- Mr. Jolly's Chocolate Factory
- The Watermill
- The Lighthouse
- Tidmouth Beach
- The Washdown
- Brendam Docks
- This episode was originally titled "Puff Puff Pastry."
- When Percy comes to a stop once he has crashed through the other side of the factory, CGI smoke is used until real smoke appears.
- This story's plot has some similarities to a magazine story with the same name.
- Alec Baldwin gives Harold a Cockney accent in this episode.
- In Days Out with Thomas' US Events, Percy tells the story of this episode with Christopher Ragland voicing Percy since his introduction in 2014. He tells the story word-for-word, but it is altered to a first-person narration.
- The shot of Percy sliding down the hill shouting "Oh no!" is shot in a 4:3 aspect ratio, as opposed to the 16:9 aspect ratio the rest of the episode was shot in.
- A behind the scenes picture shows that Mavis was the engine pushing the breakdown train in the yard when Duck brought Percy back to the sheds.
- The logo of Mr. Jolly's Chocolate Factory shown in a picture of Percy after his accident is now in possesion of Twitter user Thomas Merchandise.
- When Percy has his accident, the chocolate covering him looks fresh. But in promotional images and rare pictures, the chocolate on him looks dry.
- The LT Warehouse from TUGS can be seen when percy is loading trucks at the docks the aformentioned wherehouse also appeered in Cranky Bugs
- At the beginning, Clarabel is facing the wrong way and Oliver has Duck's whistle sound.
- Harold's unhappy expression is visible behind his happy expression when he says "Hello, Percy!"
- The narrator says "Back at the sheds, everyone thought it was very funny," but Gordon does not seem amused.
- Percy's chocolate vans and breakvan are nowhere to be seen in the close-up of him sliding down Gordon's Hill.
- In the scene where the chocolate splats out of the factory's windows, Percy's train was not seen entering the factory.
- In the first close-up of Percy covered in chocolate over the flatbed, the chocolate looks fresh. However, in the next close-up, it looks dry the same it was when Percy pulls out of the factory.
- Percy: [after all his literally dirty work] From now on, I am only doing work where I won't get dirty!
- (Percy returns to the sheds, covered in chocolate)
- Narrator: Back at the sheds, everyone thought it was very funny.
- Thomas: You look good enough to eat!
- James: UK: Pudding Percy!/US: Bon Bon Percy!
- Henry: Choc ice on wheels!
- Gordon: Disgraceful!
- The Fat Controller: Ahem! You have had a trying day, Percy.
- Percy: (from beneath the chocolate) Yes, sir.
- The Fat Controller: But you showed us all that usefulness does come before cleanliness. So, you shall have your washdown....
- Percy: Oh, sir!
- The Fat Controller: ...and a new coat of paint!
- Narrator: Percy just beamed!
- Take-n-Play (under the name "Percy's Sweet Shoppe;" discontinued)
- Wooden Railway (discontinued)
- Motor Road and Rail (UK version discontinued)
- Wind-up Trains
- Limited Edition Collection
- Motorized Railway
- Ofuro de MiniCar
- Books - Percy's Chocolate Crunch, Percy's Chocolate Crunch and other Thomas the Tank Engine Stories and Thomas, Percy and the Chocolate Express (Germany only)
- Magazine Stories - Dirty Percy! and Dirty Work