Woolly Bear is the twenty-fifth episode ever made in Season 2.
In Summer, long hay grows beside the line, which gangers cut and rake into heaps to dry in the sun. Percy will then collect the hay in empty trucks and take 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 cross. 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 a 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 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 crossly for a late Percy. Suddenly, all the passengers start laughing when Percy arrives as he is now completely covered in hay, making him quite a sight. Thomas laughs that the caterpillar has crawled out of the hay. Percy does not know what Thomas is taking 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 funny at all.
- Toby gains an extra truck and a different brakevan while puffing through the valley.