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 have 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 slide 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 the hat Mr. Bubbles was wearing looked similar to the "funny" temporary funnel Thomas had to wear.
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 is a clown who loves to entertain children with his talents of bubble-blowing and balloon modelling. He can be very jovial, funny and silly but also be stern if necessary.
Mr. Bubbles wears yellow overalls with red polka dots over a black and white striped shirt, with an oversized green bow tie and a green bowler hat. He has blue hair, wears clown make-up and a red nose on his face.
- Keith Wickham (UK; thirteenth series onwards - US; Bubbling Boilers onwards)
- Michael Brandon (US; thirteenth - fifteenth series)
- Nobuaki Kanemitsu (Japan)
- Ernesto Lezama (Latin America)
- Fabian Harloff (Germany)
- Bernard Demory (France and French speaking Canada)
- Christian Greger Strøm (Norway; thirteenth - fifteenth series)
- Jarosław Domin (Poland)
- Jukka Voutilainen (Finland)
- Haris Grigoropoulos (Greece)
- In the twelfth series episode, Thomas and the Billboard, he is known as "Mr. Giggles" before being renamed Mr. Bubbles in the thirteenth series.
- In the Norwegian narration, Mr. Bubbles is called "Mr. Bubbleman".
- In the European Spanish narration, Mr. Bubbles is called "Mr. Balloons".
- In Thomas & Friends in 4-D: Bubbling Boilers, Mr. Bubbles' hairstyle changed. Also in the twenty-first series, his red nose became larger.