|This article is about the episode. You may be looking for the Buzz Book or the magazine story.|
In summer, long hay grows beside the line and gangers cut it and rake it into heaps to dry in the sun. Percy would then collect the hay in empty trucks and takes them to the station. There Toby would collect the trucks and take them into the hills for farmers to feed their animals.
One day, Percy arrives at the station and starts to tease Thomas for thinking he was a ghost. Thomas retorts that Percy is a "green caterpillar with red stripes", which makes Percy angry. Thomas then reminds Percy that he has been late at the station every afternoon that week. Percy tells Thomas that it is the hay that is making him late, but Thomas is not interested in Percy's excuses and leaves.
Percy grumbles to himself all that afternoon that he is only ever late by a few minutes, but nevertheless he and his driver decide to head to the station early and go to the harbour to drop off some trucks. However, a crate of treacle hanging over Percy drops and splatters all over him. The workmen at the harbour try to clean him up, but Percy has to leave and is still very sticky when he does.
Soon Percy comes to the hill where the hay is laying and by now it is very windy. The hay is blown over the track and Percy. Because Percy's wheels slip on the slippery hay he must wait for the line to be cleared. While he does so, the wind blows some of the hay onto Percy, where it sticks due to the treacle.
At the station, Thomas waits angrily for a late Percy. Suddenly, all the passengers start laughing when Percy arrives as he is now completely covered with hay, making him quite a sight. Thomas laughs that the caterpillar has crawled out of the hay. Percy does not know what Thomas is talking about, but Thomas tells him that seeing Percy like this is worth being late.
Percy runs back to the shed where his driver shows him what he looks like in a mirror. Now Percy knows what everyone was laughing at, stating that he looks like a woolly bear and asks to be cleaned before Toby arrives, not knowing that Thomas has already told Toby everything.
In the end, it does not matter, as by the time Toby and Thomas arrive, Percy is still a long way from being cleaned causing the two to make jokes about woolly bear caterpillars. Percy does not find these jokes very funny at all.
- Toby (does not speak)
- Annie and Clarabel (cameo)
- Jem Cole (cameo)
- Sir Topham Hatt (mentioned)
- This episode is based on the story of the same name from The Railway Series book, Tramway Engines.
- The Italian title of this episode is "The Green Centipede". The German title is "The Wolly Bear". In Japan, this episode is called "Percy Became a Caterpillar". Its Welsh title is, "Caterpillars" in Latin America, this episode is called "Thomas Have Fun".
- Stock footage from Percy Runs Away and Percy and Harold is used.
- Toby gains an extra truck and a different brakevan while puffing through the valley.
- Percy's brakevan disappears as he enters the harbour.
- Look at Percy when the treacle lands on him to see the reflection of the studio.
- The narrator says that "Percy was cross" when he had his sad face.
- In the close-up of Percy's wheels struggling in the hay, a gear is seen behind one of them.
- When Percy arrives at Ffarquhar, hay bales appear in his trucks.
- When Percy looks in the mirror, studio equipment is visible in the top-left corner.
- The sound of the treacle landing on Percy is delayed in the restored version.
- The narrator said that Thomas was laughing when he saw Percy, but Thomas looks grumpy.
- In the restored version, when Thomas and Toby back into the shed, Toby stops slightly outside of the shed. But in the next scene, he is further in.
- In a rare still from the episode, Percy's eyes are wonky as he pulls his train.
- Throughout the episode, Percy's left (viewer's right) cylinder is dangling and wobbling.
- The treacle landed in the middle of Percy's Boiler. How can it be all over his face?
- "Wheeeeeeeeeeesh! Don't be frightened, Thomas. It's only me!"
- "Your ugly fizz is enough to frighten anyone. You're like-"
- "Ugly indeed! I'm-"
- "A green caterpillar with red stripes. You crawl like one too."
- "I don't."
- "Who's been late every afternoon this week?"
- "It's the hay."
- "I can't help that. Time's time, and the Fat Controller relies on me to keep it. I can't if you crawl in the hay till all hours."
- An argument between Percy and Thomas