When Brady first arrived along with Olivia, he immediately wanted to go to the Other Railway to save Kylie from scrap. He,along with Emily, Olivia, and Rusty later did save Kylie from scrap , and, a little while later, also saved Benjamin from scrap .
When City of Truro visited in the second season, he spent a lot of time with Duck, which made Brady jealous. Because of this, Brady was rude to City of Truro. However, since City of Truro saved Brady from falling off the broken viaduct, the two are firm friends .
In the fifth season, Brady competed in the Great Engine Games. However, during the competition, Brady crashed a cylinder . After the competition, Brady became friends with Hiro while they were both being repaired at the Sodor Steamworks. Later. Brady became friends with Ryan and Daisy when he was sent to help out on their branch line. Also in that season, Brady competed on Jacob's trivia game, alongside Emily, Benjamin, Olivia, and Kylie. A Team Sterling, the five of them made it to the semi-final round before losing to the eventual winners, Team Great Western, which consisted of Duck, Oliver, Jackie, and Toad. During the final round, Brady cheered for Team Great Western instead of Team Class 08, which consisted of Diesel, Rose, Sidney, and Paxton. Diesel was hurt by this, and managed to keep his distance from Brady the days following the trivia game. However, Brady would later apologize and the two would be friends once again .
In the seventh season, when Gordon decided to stay in the shed one morning, Brady was given the job of taking the express . Later on in that same season, Brady and Benjamin were ploughing the line up to Crovan's Gate. When they got there. Brady stopped to talk to Skarloey. However, Marie came up behind them with the Express. She ran into Benjamin, damaging both him and his snowplough. Benjamin tried to tell Brady, but he wouldn't listen. However, when the pair got to Gordon's Hill, Benjamin broke down, and the two nearly had an accident with Neville and his goods train .
In the ninth season, Brady and Marie compete with each other when taking fans and players to the Great Waterton football game . Brady was also angered when Marie and Rose said that Richard Hatt leaving Jacob and Sierra in charge of the railway was a bad idea.
In the eleventh season, during a heavy fog, Brady almost had an accident with Madison, Olivia, and Rebecca due to the poor visibility.
Brady is a kind engine. He is liked by everyone, even Diesel, who is one of his best friends. He is, however, known to tease his twin, Benjamin, as well as Kylie, one of his closest friends.
Brady is based on a Great Northern Railway G3 Stirling Single 4-2-2. Designed by Patrick Stirling in 1870 with 8ft 1in driving wheels and outside cylinders, they were specifically built for high speed expresses between London and York. These locomotives were capable of hauling 280 ton trains at 50 mph, though they could reach 85 mph on lighter services. A total of 53 were built at Doncaster between 1870 and 1895, in three series introduced in 1870, 1884 and 1894 respectively; the last was withdrawn in 1916. The only surviving member of his class (No. 1) is on display at the National Railway Museum.
When Brady first arrived on Sodor, he was painted dark blue with black lining, running board, and wheels. He also had his name written in black on his tender. In Saving Benjamin, Brady was repainted in light green with dark blue lining. He has his name and number on his tender in blue. He also had a chocolate colored running board until the tenth season, when his running board became red.
Brady has gone through a few aesthetic changes throughout the years:
It was revealed in the tenth season episode, Brady's Christmas Wish that Brady can speak and understand French. This makes him the third engine to speak French, with the other two being Millie and Daisy.