"Parties are my specialty!"
-- Thomas, Luke and the Special Party, first season
Thomas is a blue tank engine. He is very cheeky, and often plays tricks on the other engines, mostly Gordon.
- Season 1 - Races, Luke and the Special Party, Where's BoCo?, Repairing Old Slow Coach, The New Diesel Fuel (does not speak), Bertie and the Fog, Thomas and the Kitten, James and the Ice Cream (does not speak), Making Fun (does not speak), Flora's New Coach (cameo), Sodor Blackout, and Hiro Goes Home
- Season 2 - Thomas and the New House, Dennis and Norman, Off to the Scrapyards, Hank Goes Fishing (mentioned), Dares, Water Cannons (does not speak), Toby and Carol and Sidney's First Christmas
- Season 3 - Thomas and the Twins, Where is Sir Topham Hatt?, The Singing Woman (cameo), Worriful Whiff, A Train for the Queen, Hector the Ballast Hopper (mentioned), The Great Boiler Ache Caper, and Percy and the Storm,
- Season 4 - Finally at Home! (cameo), Flora and Koby, Koby and Bumble, Streamlined Engines (mentioned), Saving Jack, Hooray for Hiro, Welcome Back, Jack!, Thomas Does His Thing, and Thomas, Percy and the Hurricane
- Season 5 - Gordon Gets Crushed, Diesel and the Famous Visitors, Nigel (does not speak), Diesel Domination, Wheels of Fortune, Whistles!, James and Flynn, Harvey and the Railway Inspecters (cameo), Percy Falls For It, Thomas Gets Juiced, Thomas Runs Away, and "It's A Great Story After All....."
- Season 6 - The Faulty Sheds, Hank's State: Worried, The Wrong Sort of Coal,
- Season 7 - Don't Leave your Branchline, Billy's Comeupance (does not speak), Henry the Wedding Engine
- Season 8 - Thomas and the Visitor, Thomas, Percy and the Important Train, Mystery of the Stolen Honda
|North Western Railway|
|Thomas • Edward • Henry • Gordon • James • Percy • Toby • Duck • Donald and Douglas • Oliver • Barry • Charles • Charlie • Eagle • Daisy • BoCo • Bear • Pip and Emma • Jason • Derek • Diesel 10 • Splatter and Dodge • Salty • Emily • Harvey • Arthur • Fergus • Murdoch • Diesel • Molly • Neville • Dennis • Rosie • Whiff • Billy • Hank • Flora • Scruff • Den • Dart • Norman • Paxton • Sidney • Belle • Porter • Gator • Patriot • Dave • Mark • Wilson • Brian • Vegard • Stafford • Jonathan • Phillip • Winston • Flynn • Brandon|