Series 12

The twelfth season of the television series aired in 2008. The twenty episodes were narrated by Michael Angelis in the UK and Michael Brandon in the US.

Episodes

 * 1) Thomas and the Billboard - Diesel obscures Thomas in a photograph of the engines.
 * 2) Steady Eddie - Edward takes the Great Waterton water wheel on the scenic route to show off to his friends.
 * 3) Rosie's Funfair Special/Rosie's Carnival Special - Rosie and Emily are pulling a train for a fair, but Rosie wants to pull it alone.
 * 4) Mountain Marvel - Peter Sam rushes to finish his jobs in order to hear a tale about Proteus from the famous storyteller, Miss Marvel.
 * 5) Henry Gets It Wrong - Henry worries that the workmen are going to cut down the wishing tree.
 * 6) Heave Ho Thomas! - A large new engine called Hank arrives, but Thomas is determined not to need his help.
 * 7) Toby's Special Surprise - Toby wants to make an impression by searching Sodor for something special.
 * 8) Excellent Emily - Emily becomes arrogant after receiving praise from the Fat Controller.
 * 9) The Party Surprise - Freddie decides to reorganize a winter party at Mr. Percival's house as a surprise for Colin the crane.
 * 10) Saved You! - Thomas wants to prove his heroism when he learns a fireman is to be honoured.
 * 11) Duncan and the Hot Air Balloon - Mr. Percival's twins are getting a ride in the Hot Air Balloon for their birthday, but Duncan wants to take them himself.
 * 12) James Works It Out - When James ignores Hector's advice, he gets caught in bad winter weather.
 * 13) Tram Trouble - Toby and Flora are heading a parade at Great Waterton; Thomas thinks Toby would rather lead the event on his own and tries to distract Flora.
 * 14) Don't Go Back - Thomas and Diesel race backwards.
 * 15) Gordon Takes a Shortcut - Gordon gets lost while taking a shortcut and refuses to ask for help.
 * 16) The Man in the Hills - Thomas and the narrow gauge engines collect presents for Mr. Percival's birthday.
 * 17) Thomas Puts the Brakes On - Thomas' brakes malfunction while delivering bricks to repair a bridge.
 * 18) Percy and the Bandstand - Percy is tasked with bringing Lady Hatt to a surprise party - but the unknowing Lady Hatt tells him to go elsewhere.
 * 19) Push Me, Pull You - Skarloey refuses Rheneas' help to pull a train for a puppet show and ends up playing the trucks' games.
 * 20) Best Friends - Thomas tries to avoid telling Percy he has been given a job Percy wants to do.

Characters

 * Thomas
 * Edward
 * Henry
 * Gordon
 * James
 * Percy
 * Toby
 * Duck
 * Donald and Douglas
 * Oliver
 * Ben
 * Emily
 * Murdoch
 * Neville
 * Rosie
 * Whiff
 * Stanley
 * Diesel
 * Mavis
 * Salty
 * Skarloey
 * Rheneas
 * Sir Handel
 * Peter Sam
 * Duncan
 * Freddie
 * Mighty Mac
 * Rusty
 * Toad
 * Hector
 * Bertie
 * Jack
 * Harold
 * Sir Topham Hatt
 * Lady Hatt
 * Stepney (does not speak in UK version)
 * Arthur (does not speak)
 * Harvey (does not speak)
 * 'Arry and Bert (do not speak)
 * Annie and Clarabel (do not speak)
 * Henrietta (does not speak)
 * Rocky (does not speak)
 * Trevor (does not speak)
 * Alfie (does not speak)
 * Cranky (does not speak)
 * Jeremy (does not speak)
 * Dowager Hatt (does not speak)
 * Miss Jenny (does not speak)
 * Sodor Brass Band (does not speak)
 * Bulgy (cameo)
 * Max or Monty (cameo)
 * Proteus (mentioned, seen as a statue)
 * The Mayor of Sodor (mentioned)
 * Dennis (learning segment)

Characters introduced

 * Colin
 * Hank
 * Flora
 * The Tree Specialists (do not speak)
 * Mr. Giggles (does not speak)
 * The Teacher (cameo)

Trivia

 * This is the first season to use CGI.
 * This is the last season to use models and clay faces. The clay faces are used in background shots.
 * This is the first season to have all of the human and animal characters and Harold in full CGI.
 * This is the first season to only have twenty episodes.
 * This is the last season to be filmed at Shepperton Studios.
 * This is TV series veteran Steve Asquith's final season.
 * Pierce Brosnan was originally going to narrate this season, but was later replaced by Michael Angelis and Michael Brandon for unknown reasons.
 * This was the last season to have all of the characters voiced by the narrator.
 * This is the first season not to be shown on Japanese TV, but has been shown exclusively at Thomas Land's 3D Theatre in Japan.
 * In the UK, this season was supposed to be shown after The Great Discovery, but was brought forwards for unknown reasons.