Percy

Percy is a little green saddle tank engine who was brought to Sodor to help run the railway during Gordon, Henry and James' strike. He is one of the youngest engines on Sodor and he is also Thomas' best friend and is quite cheeky, often getting himself into trouble with his attempts to play tricks on the other engines. Percy's favourite job is to deliver the mail and he works on Thomas' Branch Line as a goods engine.

Personality
Percy is a rather cheeky, but kind engine. He normally behaves well, yet he also gets himself in trouble by jumping into situations without adequately thinking them through first. He loves teasing other engines, especially bigger ones such as Gordon and James, but is always brought down to earth in due course by anyone who gives him the moral to learn, especially the Fat Controller. He can also be somewhat timid.

Percy can also be questionable and naïve to certain difficult words: he would say "depotstation" whereas anyone else would say "deputation", "dingy-fried" instead of "dignified", "dimmer-station" instead of "demonstration", "inspectacles" instead of "inspector", "tenkiakihos" instead of "technology" etc.

Percy is incredibly accident-prone and has many accidents, sometimes due to his own silliness or his tricks backfiring. He holds the dubious record of the most accidents in one series - five, all of which happened in the second series; crashing into some buffers, falling into the sea, being pushed onto a brake van, colliding with a cart of lime and being hit by a falling crate of treacle. His silliest accident to date, however, was in the sixth series, when he slipped on oily rails and crashed through the chocolate factory and emerged covered in chocolate. Despite this, he always tries to do his best, learns from his mistakes and get his jobs done, a loyalty which the Fat Controller has praised him for on many occasions.

Although their friendship has been turbulent at times, Thomas is Percy's best friend. He is also good friends with Toby. While he has a small rivalry with Harold stemming from their race, they are always willing to help each other when in trouble.

Percy can also be seen as an easy target for teasing by the big engines, more particularly Gordon and James, especially whenever he has an accident or when he is afraid of something. He also has held a grudge against Gordon and James about their fooling him into misinterpreting a signal but silenced this with some help from Duck. This shows that, when nonsense goes too far, Percy will not stand for it and seek help to settle the matter for good, even if he faces a reprimanding from the Fat Controller for it.

In the fifth series, Percy is vaguely the same engine he's always been. However, he became annoyed rather easily and unhappy with his work amount while the other engines, except Toby, thought even less of him.

During the CGI series, Percy became slightly wiser and a little less cheekier. This could be because he learnt his lesson for being cheeky or because he did not want to get in trouble again. Also, Percy and Thomas' friendship has expanded and they hardly ever argued. Despite his increased maturity, Percy still falls victim to occasional bouts of naivety and misunderstandings.

Basis
Percy is an 0-4-0 saddle tank believed to have been built by the Avonside Engine Company of Bristol, but prior to being purchased second or third hand by the Fat Controller he acquired components from Hunslet of Leeds and other builders.

In the My Thomas Story Library book, The Fat Controller, a maroon tank engine seen in the workshop vaguely resembles Percy, so it is likely that the engine also has the same basis as Percy and the same modifications as him.

In the later volumes of the Railway Series, Percy's saddle tank is depicted with a semi-circular profile, whereas in the earlier volumes and the television series, his saddle tank had an ovular profile.

Livery
Percy is painted in NWR apple green with red and yellow lining. His number 6 is painted on the sides of his cab in yellow with red lining and the lining around his cab windows is yellow. In some illustrations, he has grey coal rails, whereas in the later volumes of the Railway Series they are the same green as his bodywork. In the television series, Percy's coal rails were painted black.

In some illustrations of the Railway Series, Percy has a golden builder's plate on the side of his cab.

Television Series

 * Season 1 - Stepney's Problem, A Scottish Tale, Toby and the New Engine, Duties of the Diesels (cameo), Wilbert to the Rescue, Wilbert and Tiger Moth (cameo), Frank and the Trucks and Gordon Plays a Trick
 * Season 2 - Daisy and the Visitor (cameo), James' Tender Trouble, A Flying Surprise (does not speak), Twin Trouble (cameo), Old Slow Coach (mentioned), The Flying Scotsman Returns and Save Sir Topham Hatt!
 * Season 3 - TBA
 * Season 4 - Rosie's Wild Ride
 * Season 5 - TBA
 * Season 6 - TBA
 * Season 7 - TBA
 * Season 8 - TBA
 * Season 9 - Tender Bender
 * Season 10 - Bee Yourself, James, Mike Goes on Strike, Coal Crisis (cameo) and Groundhog Gordon
 * Season 11 - Big City Rumor, Duncan in the Dumps (cameo), Just Duck's Luck, Spencer Goes Too Far and Holly Jolly Molly
 * Season 12 - Greetings, Montague!, Percy Gets a Promotion, Henry's Handcar Havoc (mentioned) and Bulgy Takes the High Road
 * Season 13 - It's Good To Be Belle (cameo), Victor's Loco Motives, The Duke of Hazard (cameo), Who Stole The Coal?, Ivo Hugh's Day at the Zoo (cameo), Hector and Logan's Hot Pursuit and How Gator Stole Christmas (cameo)
 * Season 14 - Double-Decker-Wrecker (cameo), Hiro and the Heat Wave, Furious George and S.C. Ruffey's Sweet Tooth (cameo)
 * Season 15 - For Whom The Belle Tolls and The Island of Misfit Engines
 * Season 16 - Henry's Hill, Marion Had a Little Lamb (cameo), Painting the Rosie's Red, Paxman Pulls Through (cameo), Throw Topham from the Train, Ace in the Hole (cameo) and Finding Lorry
 * Season 17 - Unidentified Flying Scotsman (cameo), Bold Slow Coach (cameo), Big Trouble on the Little Western (cameo), Oliver Confusion, Diesel Gets the Bronze (cameo), James and the Giant Screech (cameo), Toby, Or Not Toby and Thomas' Crown Affair (mentioned)

Specials

 * Oliver's Eleven
 * Saving Pirate Ryan

Trivia

 * One of Percy's models is currently on display in Japan at the Hara Model Railway Museum and is wearing his smiling face mask (previously on display at Nitrogen Studios), along with his large-scale model used for the spin-off series, The Pack (previously on display at Thomas Town). Three of Percy's face masks are also in possession of Twitter user ThomasTankMerch.
 * Percy is the only engine who is known to have been named by the Fat Controller.
 * Percy is the first engine in the series to have only four wheels.
 * In the French narration of the first seven series, Percy is called "Pierre".
 * In the Greek narration of the first seven series, Percy is called "Jerry". From the thirteenth series onwards, Percy has been referred to with his original name.
 * Percy has been shown to be quite popular among several people who worked on the series:
 * According to Abi Grant on her website, Percy is her favourite character.
 * Britt Allcroft also stated he was her favourite character (due to him being green and cheeky).
 * Percy is also Mark Moraghan's favourite character, alongside Cranky.
 * Mike O'Donnell also has Percy down as a favourite for being a "cheeky little chap".
 * Percy is the first character other than Thomas to be the protagonist in a special, with that special being Day of the Diesels, which he would later do again in Tale of the Brave.
 * In Thomas and the Rumours, Percy is stated to have a branch line, though it may have been mistaken for Thomas' Branch Line.
 * His whistle in the US version of Thomas and Stepney was reused for Stanley in the twelfth series.
 * He is one of the few characters created by Wilbert Awdry who is not precisely based on a real engine.
 * Percy was featured on the 1986 single cover along with Rheneas of Oh L'amour, a song by English synthpop duo Erasure.
 * In a 2020 Australian Red Nose Day advertisement, a child is seen playing with a 2014 My First Percy and an Ertl Gordon.
 * Percy's third series whistle sound was reused for Toby in the fourth series episodes Bulls Eyes and Special Attraction and also for Logan in Welcome to the Island of Sodor, Logan!
 * Percy has the same whistle sound as Edward's, albeit in an octave higher in pitch.
 * The outline of Percy's Hornby Model was featured in the introduction sequence of the first season of James May's Man Lab.
 * Percy is the only current Steam Team member not to have lining on the back of his bunker or tender.
 * Percy's Gauge 1 model had a total of nineteen facial expressions during the model series era, two of which (different smiling and alternative astonished) were not used on-screen.
 * His Pack-Scale model had a total of six facial expressions, two of which were not used on-screen.
 * Despite being titled the small engine, Percy is much wider than Thomas in the model series of the original show. However, Thomas is longer and slightly taller. In the CGI series, Percy is depicted more clearly as shorter than Thomas in both length and height, but he ultimately remains wider. In All Engines Go, Thomas is depicted as definitively bigger than Percy.