Mr. Bubbles (also known as Kuffy and Mr. Giggles) is a clown famous for blowing very big bubbles and performing with very large balloons.
He first went by the name "Kuffy" when the circus came to the Island of Sodor. When entertaining some children at Mountain Village Station he gave Freddie his bells when he was looking for one as Mr. Percival's new bicycle did not had one. Kuffy later attended the opening ceremony of Great Waterton and entertained some children at Knapford as "Mr. Giggles".
Mr. Bubbles later attended a bubble show at the Town Square using his special bubble liquid that was imported. The Fat Controller drove him to the show, though they were delayed due to Thomas spilling the liquid, which caused his car to slid off the roads. Mr. Bubbles was disappointed with Thomas, though he gave him a second chance to bring another barrel of his bubble liquid. At the show, Thomas noticed that Mr. Bubbles' hat that he wore looks similar to his "funny funnel".
Once, Thomas was assigned to take some of Mr. Bubbles' bubble mixture to a special celebration. However, an incident at Brendam Docks caused the mixture to fall on Thomas, which caused him to puff bubbles and have an accident. Thanks to Cranky and his seagull friend Stuart, Thomas was found and Mr. Bubbles accompanied the Fat Controller to the accident site. There he revealed Thomas' incident had given him an idea on how to make the celebration the "bubbliest ever". At the celebration, he arrived on a flatbed with his "amazing" Bubble Machine.
Mr. Bubbles wears yellow overalls with red red spots over a black and white stripped shirt, with a oversized green bow tie and a green bowler hat. He wears clown make-up and a red nose on his face.
- Keith Wickham (UK; thirteenth season onwards - US; Thomas & Friends in 4-D: Bubbling Boilers onwards)
- Michael Brandon (US; thirteenth-fifteenth seasons)
- Nobuaki Kanemitsu (Japan)
- Ernesto Lezama (Latin America)
- Fabian Harloff (Germany)
- Bernard Demory (France and French speaking Canada)
- Christian Greger Strøm (Norway; thirteenth-fifteenth seasons)
- Jarosław Domin (Poland; thirteenth season onwards)
- Jukka Voutilaninen (Finland; thirteenth season onwards)
- In the Norwegian narration, Mr. Bubbles is called "Mr. Bubbleman".
- The hat he wears during performances looks like a funnel Thomas once had to wear.
- In Thomas & Friends in 4-D: Bubbling Boilers, Mr. Bubbles' hairstyle changed.