- "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 was tricked by Bill and Ben when they challenged him to a race and he almost collided with Henry's goods train after he was trying to beat them.
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.