Prince Harry has filmed a special introduction for Thomas & Friends: The Royal Engine.
The show is to mark the children's show's 75th anniversary and will air this weekend.
Harry admitted he's "proud" to be part of the project.
What has he said?
He said: "Thomas the Tank Engine has been a comforting, familiar face to so many families over the last 75 years.
"Entertaining, educating and inspiring children on important issues through exciting stories and characters."
"I certainly have fond memories of growing up with Thomas & Friends and being transported to new places through his adventures.
"I'm very proud to have been asked to take part in this special episode. I wish Thomas & Friends a very happy anniversary."
Meanwhile, Harry filmed his introduction in January and also made a donation to charity.
The 22-minute episode features some unique characters including Queen Elizabeth II, and the Prince of Wales as a child.
Meanwhile, Rosamund Pike will be voicing the titular Royal Engine.
The actress hailed her role as an "absolute honour".
What did she say?
She said: "It is an absolute honour to have the chance to appear in the show.
"I take it as a big responsibility to play Duchess, who is a lovely, warm, bubbly sort of effervescent engine."
In the special, Sir Topham Hatt has been invited to London by the Queen to receive an award.
It's for distinguished service to the railway.
Her son Prince Charles has asked that Thomas be the engine to bring him to the Mainland.
Chuck Scothon, SVP and GM of Infant and Preschool, Mattel, said: "Thomas & Friends has celebrated friendship and teamwork through storytelling.
"This has cultivated fan love across generations.
"We are releasing more storytelling content than ever before to engage the next generation of fans.
"We are thrilled Harry, The Duke of Sussex is introducing this special."
Thomas & Friends: The Royal Engine will air on Channel 5 Milkshake!, Saturday, May 2, at 9.05am.
Leave us a comment on our Facebook page @EntertainmentDailyFix and let us know what you think of this story.