Harold is a helicopter who patrols the Island of Sodor, searching for emergencies.
When Harold first met Percy, he stated that railways were "slow and out-of-date", but was proven wrong when Percy beat him in a race. When Thomas' brakes failed while boarding at a station, with an inspector Harold chased him down the line. Christmas that year Harold brought Santa Claus to the party at Tidmouth Station. Harold also dropped hot drinks for Percy's crew when they were stranded in a floating river and made friends with Duck after rescuing an injured sailor.
Harold speaks in a manner reminiscent of an RAF pilot, using terms such as "wizard" and "old chap" in conversation.
Harold somewhat tends to be full of himself as he feels that "railways are slow", but he always gets his comeuppance in the end.
Harold is based on a Sikorsky S-55 helicopter, built in the UK as the Westland Whirlwind. He has added floats.
Harold is painted white with red lining.
- Kevin Frank (Thomas and the Magic Railroad)
- In the second season, Harold's spinning rotors were achieved using a transparent disk.
- During the third and fifth seasons, Harold's rotor blades were flimsy and they bend a bit.
- Harold's television series model did not have moving eyes until the tenth season.
- In the early seasons, Harold would sometimes be given a searchlight, such as in The Runaway, Thomas and the Missing Christmas Tree, and Thomas, Percy and the Post Train.
- In the television series, Harold has never had eyebrows.
- Harold was called Herbert in French in the Classic Series.
- "Hello. Who are you?"
- "I'm Harold. Who are you?"
- "I'm Percy. What whirley great arms you've got!"
- "They're nice arms. I can hover like a bird. Don't you wish you could hover?"
- "Certainly not! I like my rails, thank you."
- "I think railways are slow. They're not much use and quite out of date."
- A conversation between Percy and Harold in Percy and Harold
- "Bother! It's that dizzy-thing, Harold!"
- "Good morning! I always said railways where out of date, but you're so slow with the post, you should give everyone their stamps back post-haste!"
- A conversation between Harold and a behind-schedule Percy in Thomas, Percy and the Mail Train
- "Harold told me you where uh.....a wizard. He told me he can beat you at somethings but not at being a submarine. I honestly don't know what you two get up to sometimes but I do know you are a really, useful engine."
-Sir Topham Hat, after Percy taking a swim in Percy's Promise.
- ERTL (normal and Gold Rail; both discontinued)
- Wooden Railway (normal and with magnet)
- Take-Along (normal and with magnet; discontinued)
- Lionel Trains (discontinued)
- Bandai Tecs
- Wind-up (normal and metallic)
|Harold • Bulstrode • P. S. Cumberland • S.S. Kathryn • Dignity • Mermaid • North Star|
|Cranky • S.S. Roxstar • Lucinda • Tiger Moth • The Queen of Sodor • The Cranes • Tugboats • The Aeroplane • The Salvage Barges • The Canal Boats • The Mail Boat • The Paddle Boat • The Fultan Ferry • The Tramp Steamer • The Hot Air Balloon|