Thomas is described as being a cheeky engine. He often gets into scrapes, usually by being over-eager to do things best left to bigger and more sensible engines. But clouds never last long in Thomas' life and he is soon bustling about again, playing his part in the yard and on his very own branch line, of which he is extremely proud. He loves teasing the others, especially the bigger engines, such as Gordon and on occasion brags about his superiority, but is always brought down to earth in due course by anyone willing to correct him, especially the Fat Controller and his two coaches, Annie and Clarabel. If Thomas has one major character flaw, it is that he is forgetful and rather impatient. However, he is also cheerful, optimistic, idealistic, altruistic, kind-hearted, supportive and helpful. A friend to all engines and a popular member of the Fat Controller's railway, Thomas is No.1 and does his best every day to live up to that through helping his friends and those that he cares about. He lives to be a Really Useful Engine and encourages everyone else to do the same. He likes to be better than James and Bertie in races. He can, however, also get annoyed about being useful such as the time when Rosie followed him around because she used to idolise him so much. Because of his popularity amongst his fellow engines and the people of the railway, Thomas often likes to view himself as a leader to the other engines. He is quick to take action when necessary and - despite the dangers or fears he might experience - has a strong sense of bravery and will never leave any of his friends behind, even despite any previous conflicts. Because of this, the other engines often follow in his tracks. However, he can feel jealous or threatened if he feels a newer tank engine is trying to replace him, as shown with Stanley and Ryan. But in the end, Thomas is always willing to make amends with those whom he previously distrusted, proving his leadership. Thomas was infamously known for his dislike of wearing a snowplough, often claiming his to be heavy and uncomfortable. On numerous occasions, he has shown he has no problems with doing anything to avoid wearing one, from banging it around to leaving it in disrepair and leaving it on a siding by claiming it did not fit properly. He does always get his comeuppance for these deeds, however, and knows that having a snowplough is important in bad snowy weather. He tolerates wearing a plough much better in the present day, but Thomas will still groan about it if given the chance, particularly when other engines make fun of him for this. While most of the other engines and especially Annie and Clarabel tolerate his slight ego to a bare minimum, Thomas has often found himself going too far, driving away even close friends such as Percy, Toby, and even Edward. When these occasions happen, Thomas is very good at luring back friends when motivated, often pulling through his personal distastes to help others out and rekindle friendships. Despite all this, he does have his pride and will sometimes take wrong advice at the wrong time - such as from Sailor John or Ace, as well as refusing help even when he needs it. Thomas also highly despises the smell of fish, and as such, when he once had the job of delivering fish, he wanted to finish quickly to avoid the smell, and ignored instructions, causing confusion and delay doing so. Thomas is painted in NWR cerulean with red lining on his tanks and boiler and yellow lining around his windows. His number (1) is painted on his side tanks in yellow with a red outline. He has a white running board with red bufferbeams and valences.