- “He must be very full of himself!"
"Racing about like that, and surprising other engines!"
"Connor's not full of himself! He's a very friendly engine.”
- ―Ben, Bill and Thomas, Bill or Ben?, seventeenth season
Connor is excitable and energetic and, like Caitlin, loves to race the other engines. Connor, however, is better at being patient, unlike Caitlin, unless he has passengers, then he can be impatient. Although it is probably unintentional, he can come across as being somewhat smug. Both Caitlin and Connor run regularly between the Mainland and Ulfstead Castle via the Vicarstown Bridge.
Soon after arriving on Sodor for his test run and time trials, Connor, along with Caitlin, helped with the search of Stephen, when the old engine went missing and, once he was found, attended the grand opening of Ulfstead Castle.
Connor later had the challenge of bringing his last passengers from Sodor home in time for Christmas. With the help of Thomas, Edward, Henry, James, Percy, Emily, Hiro and the Slip Coaches, he succeeded at getting everyone home for Christmas.
In the nineteenth season, Connor was one of the engines told about the rumour of Toby being scrapped, and later raced through Kellsthorpe Road Station, but did not see the red paint spilled onto the rails, and ended up covering Gordon's face with red spots of paint. Connor has also been seen racing with Caitlin when the latter was taking Emily to the Steamworks for repairs.
In the twentieth season, he broke his coupling rod and decided that he should go slowly until Stephen told him stories about his old days which made Connor like himself again.
In The Great Race, he almost crashed into Thomas who was on his way to the Great Railway Show.
Connor is a streamlined engine, designed for speed. Along with his friend Caitlin, Connor is an excitable and energetic character, who likes to be busy and loves to race. Both Connor and Caitlin are friendly and eager to get other engines to join in the fun with them.
Connor is based on a New York Central Railroad J-3a Hudson built by Alco of Schenectady, New York. Ten J-3a Hudsons, 5445 through 5454 were built with streamlined shrouds designed by Henry Dreyfuss in 1938 in order to do heavy hauling at a greater speed, most famously hauling the 20th Century Limited between New York City and Chicago. Following a grade crossing accident with a sand truck in East Chicago in 1945, the J-3a's had their streamlining removed. All of the NYC Hudson locomotives were scrapped.
Connor is painted teal blue with aquamarine and yellow lining. He has gold nameplates on the sides of his boiler.
- Jonathan Forbes (UK/US)
- Jan-David Rönfeldt (Germany)
- Dariusz Błażejewski (Poland)
- Scott Maurstad (Norway; King of the Railway only)
- Sigbjørn Solheim (Norway; seventeenth season only)
- Kunihiro Kawamoto (Japan)
- Christian Strempler (Latin America; King of the Railway onwards)
- Nir Ron (Israel)
- Paul Disbergen (The Netherlands)
- Bruno Marçal (Brazil; King of the Railway onwards)
- Jordi Estupiña (Spain)
- Denis Bespalyy (Russia; King of the Railway onwards)
- Jukka Voutilainen (Finland; King of the Railway onwards)
- Loukas Frangoulis (Greece)
- In real life, Connor would be too large for the British loading gauge. However, it seems that he has been re-scaled to avoid animation issues.
- Connor and Caitlin's Irish accents may be references to how the New York Central and Baltimore & Ohio employed Irish immigrants in their early years.
- Connor's Wooden Railway prototype is Spencer's toy repainted to Connor's paint scheme with the tender coupled backwards.
- Both Connor and Caitlin's CGI models have painted-on doors and windows.
- Connor has been modified to work on British railways: he has a screwlink coupling and buffers on the back of his tender. He retains a streamlined cowcatcher on the front, so he is unable to shunt. His headlamp has also been moved to accommodate his face.
- Unlike his basis, Connor has four axles on his tender instead of six.
- Connor's steam pipes (on top of his cylinders) appear disconnected from his boiler.
- In the twentieth season, Connor gained a tail-lamp and a rear brake-pipe.