- "Paxton doesn't give up easily, I'll give him that!"
- ―Diesel, Disappearing Diesels, eighteenth season
Paxton was one of the diesels who took over the Sodor Steamworks.
Upon his return to work at the quarry, Paxton overheard Luke telling Thomas about how the little green engine knocked a yellow engine into the sea. Paxton told Diesel about what he had heard. Diesel decided that Luke should be punished and set out with Paxton to expose Luke. However, Paxton felt bad and helped Thomas and Luke out by bringing Victor to talk to Luke and the Fat Controller.
Paxton almost got into a collision with Winston when he was a runaway, but luckily he stopped just in time. Afterwards, he warned Gordon to be checked over after an accident with stone. When Gordon ignored his warnings and broke down, Paxton brought him to the Steamworks to be repaired.
After Sir Topham Hatt told Paxton among other engines to be careful near the bumpy track, Paxton then messed around on the damaged track with Thomas, causing Thomas to collide with Toby. After Toby says Thomas "Lost his puff" Paxton searches for the "Puff" and makes himself look silly in front of Stephen and Victor. He then learns that "Puff" means steam. He was later used by Diesel 10 to steal Christmas decoration from Tidmouth sheds, but soon lost patience and left to collect the truck Sir Topham Hatt told him to collect.
Diesel once got the other diesels to hide from him, but Paxton eventually found him, stranded on the branch line, with no fuel, and shunted him to the next station for him to stock up.
At Christmas time, he was given the job of transporting a Christmas tree to Ulfstead Castle. But the tree caused him to derail, and when Diesel passed by, he refused to help Paxton. That night, Paxton pretended to be the Ghost of Christmas Present to try and remind Diesel of the true meaning of Christmas, but Diesel was too scared to listen and ran away.
One day, he was pulling freight when he found a train struggling on Gordon's Hill pulled by Samson along with Thomas as the back engine. He offered to help and pushed Samson and Thomas over Gordon's Hill.
Paxton is a young, gentle diesel who often works in or around the Blue Mountain Quarry and the Vicarstown Dieselworks. He is good-hearted and well meaning, but gullible, naïve, and easily misled. He also has a short attention span. He tends to be more of a follower than a leader and can sometimes find thinking for himself and making big decisions difficult. This may result in him being pressured into a situation he might not necessarily be comfortable with. However, if a friend is in trouble, Paxton will have the conscience and the self-assertion to do what he himself feels is right. As a result, the other steam engines find that he is likeable and Paxton particularly looks up to Thomas at times. He also works alongside the narrow gauge engines frequently. However, Paxton can easily misjudge situations, misplace his trust in someone who might not have everyone's best interests at heart, and is a rather impressionable diesel, but his good nature will ultimately show him for who really wants to be.
Paxton is based on a BR Class 08 diesel-electric shunter. Over seventy members of this class survive today in preservation, while around 100 remain in service on the national rail network. They were in fact the most successful shunting engines in the world, with 996 of them built. Diesel, the Diesel Shunter, 'Arry, Bert, Splatter, Dodge, Sidney, Ulli and the Mainland Diesels are other members of this class.
Paxton is painted dark green with yellow lining. His siderods and front bufferbeam are painted a rusty orange colour. His paint is chipped in places, and shows signs of weathering.
- Despite Paxton's bio claims he's always called by his nickname being "Pax", he has been consistently referred to by his full name rather than his nickname. He shares this dilemma with Norman and Sidney.
- According to the Licensing Source 2015 book, Ian McCue, former producer of Thomas & Friends, stated that Paxton is his favourite character.
- Paxton was never named in Day of the Diesels with the exception of the song.
- There have been a few occasions where Paxton has gone faster than his basis' top speed.
- Paxton has had a few changes in the television series as the series goes on:
- Season 19:
- His siderods gained a metallic hue.
- Season 21:
- He gained a tail-lamp.
- Season 19:
- "Um...er...excuse me! Um...I-I-I wonder if, er, someone could help me? M-maybe? Please?" (thud) "...Ow."
- Paxton after being buried in the rubble from Blondin Bridge, Blue Mountain Mystery
- "Hi, Stephen. Thomas lost his puff and I'm trying to find it and...well, I thought that might be...the lost puff...up there..."
- "Up there? Well, that's just a cloud..."
- "Yes, of course. I knew that. A cloud. Okay...got to go. Great to see you. Bye, Stephen."
- Paxton talking to Stephen about Thomas' "lost puff", The Lost Puff, seventeenth season