- "I know you can do great work Arthur. The Fat Controller speaks very highly of you."
- ―Avon Sharp, Snow Blind
Arthur is a big red tank engine who runs the Fishing Village Branch Line at Norramby. He also is given various shunting duties and good trains around the Island.
When Arthur first came to Sodor, he took great pride in his spotless record, gained in part thanks to his 'mentor' of a brake van, Bradford. He soon lost it however, after colliding with Duck's trucks in an incident largely provoked by Thomas and Percy. However, this spotless record was soon amended, after Thomas apologized to him for causing the accident.
He was bought to shunt and pull goods, but then was transferred to the Norramby coastal run, on which he enjoys working. He is responsible for this line, which is famous for its fish. Arthur is the only known engine (with the exception of Salty and Porter) to enjoy the smell of fish.
The Fat Controller sent him to work at the Little Western Extension Project, where the big tank engine met Wilbert the Forest Engine. The 2 became friends instantly. Later, Avon Sharp the project foreman sent Arthur to Vicarstown to collect some trucks. Arthur was there met by Paul the Mechanic, who asked Arthur to take a crate to the Transfer Yards. Arthur was happy to help, but this detour caused him to be late, getting him into trouble with the foreman. He felt irritated that he had let Paul's request get in the way of his work. He came to a siding, and tried to stop early, but slipped on the icy rails, crashing into the buffers, and getting himself stuck in an avalanche. Wilbert came to his rescue, but Arthur felt very sad about his accident. Wilbert helped him come to realize that sometimes things are simply out of his control, and the 2 engines felt content.
When Arthur was brought to the yards for shunting, he felt it dull, until Daisy told him and Murdoch about her mishap with sheep. Arthur was inspired to view shunting as "tending to the flock." However, this new mindset caused him to crash into a flatbed with crates of flour. The end result, in his mind, was "an all-encompassing shepherd's pie", and he and Murdoch had a good laugh!
During the Munitions Incident, Arthur was 1 of the 4 engines along with Edward, James, and BoCo that were told by the Fat Controller to stand by the loading area at the Ministry of Defense Complex in case of any disaster (due to General Zen's behavior). However, the General didn't want their help because of regulations and not thinking twice tried to have Muddle, Mayhem, and Filibuster kick them out and threaten to have them scrapped if they didn't listen. This plan, of course, could not stop the admirable little tank engine.
Arthur found out that Zen was transferring fuel and munitions at the same time and raced into the loading area to stop him. Zen was still to stubborn to listen and threatened to sell Arthur for scrap, but Arthur knew he couldn't back down. While Arthur and Zen were arguing, Paxton accidentally shunt some fuel into a siding causing the trucks to derail, which gave Sir Frederick Aura (who had been watching the operation from the sidelines) and Walter Richards their chance to start a fire that would end up destroying the outpost.
Arthur took charge and told the General to stay out of the situation. He later shunted a fuel tanker and a flatbed to a safer location, far from the inferno. Aided by James, they reached the canal, and Arthur decided to shunt the dangerous load into a siding. Suddenly, debris from a burning tower hit the trucks and the fuel exploded in front of him causing his buffers to melt and to derail, but the firefighters managed to save him and James from a fiery grave. Arthur, along with Edward, James, BoCo, Paxton, Derek, The Thin Controller, Darren, and a few other soldiers,were honored for everything they did to prevent the fire and save lives.
During a routine run on his branch line, Arthur stops for a drink near the Transfer Yards. During his stop, he converses with Madge and Sir Handel regarding Sir Handel's accident with Samson at Crovan's Gate Mine. After wishing them well, Arthur is surprised to see a strange etching in the cliffs above him. A passing Mighty Mac informs that the etching is the Man in the Hills, a mysterious etching which has begun appearing more frequently around the island. Arthur was intrigued by this, and departs.
Later on, Arthur met up with BoCo to ask him about the cause of the rockslide near Crovan's Gate Mine. BoCo replies that the circumstances are still shady, with the Search and Rescue Team as well as the Ministry investigating the incident. Arthur suggests informing Edward of the situation, but BoCo hesitates at doing this, due to their own uncertainty regarding the incident. Upon BoCo's mention of a Man in the Hills etching near the site, Arthur is startled that a Man in the Hills etching has also appeared there. While discussing the image, they pass Thomas, who tells them Sir Handel seems to know about the phenomena, as he once told a story about it for The Thin Controller's Birthday. Arthur resolves to ask Sir Handel about his knowledge of the Man in the Hills
Arthur was present during Richard Hatt's suggestion box presentation. When Charlie suggested he be the Knapford Station Pilot, he asked everyone if he was "right or [is he] right," to which Arthur jokingly decided that, given his options, Charlie was right.
When several famous engines came to visit Sodor, Arthur was tongue-tied at the prospect of meeting with Duchess of Hamilton, much to Murdoch's annoyance. Emily pushed Arthur over to Duchess so he could get it out of his system, and after an ice-breaker concerning Hamilton's streamlining, revealed the backstory behind his spotless record to her.
Arthur is a very obedient, intelligent, hard-working, responsible, and friendly tank engine who has never been naughty. He is always willing to help a friend in need and is willing to carry out any job. He does, however, have a tendency to get carried away and can be quite gullible at times. He also can be very innocent and impressionable, mimicking the mannerisms of engines he really admires. He sees Murdoch as a wise mentor. Occasionally, he can be a bit of a perfectionist, and is hard on himself for any mistake made. This is most likely due to the high expectations set for him by many, as he came with a spotless record, which came about after his experiences with Bradford the Brake Van.
- Season 1: Lift Bridge, Swagger and Swerves (cameo), The Old Warrior (cameo), Feeling Lucky? (cameo), Improvisation, Rising to the Occasion (cameo), Snow Blind, Shepherd's Pie, Scruff's Scaffolding (cameo), Rendezvous with Disaster (cameo), Will Power (cameo), Conspiracy Theory (flashback cameo)
- Season 2: Paxton and Norman (cameo), Two Hearts Burn Together (cameo), Mavis and the Tornado, Rosie (cameo), Waterworks (cameo), James Goes on a Trip (cameo), Rock-Star (cameo), Pummeling Percy, Tag-Team (cameo), Munitions, Blunderbuss, Swashbuckler (cameo)
- Season 3: Marion Saves the Day (cameo), This Too Shall Pass (cameo), Samson, BoCo, and the Man in the Hills, Derek and the Two Faced Engines (cameo), The Suggestion Box, Penn Pals (cameo), Ice Breaker (cameo), Percy and Asbestos, Stafford's Request (cameo)
- Web Clips: Mike and Frank Banter: SLOTLT, ScarletFire, and EE93's Return (cameo), Philip and Daisy - Meet the Characters!, Gina gives Percy some pointers - Meet the Characters! (cameo)