Percy is a cheeky green saddletank engine who was brought to Sodor to help run the railway during the big engines' strike. His favourite job is to deliver the Mail Train. He works on Thomas' Branch Line as a goods engine.
Percy is a bit silly but a sweet, cute, funny, pleasant and kind little green tank engine. Sometimes he acts cheeky, but always learns his lesson. As the television series has progressed, Percy has been dumbed-down in order to teach viewers difficult words: he would say "dingy-fried" where anyone else would say "dignified",or make "Demonstration" into " Dimer-station". He is also shown to make silly mistakes, but then fix them upon realising what he has done before further damage is caused.
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 season - five, in the second season - crashing into some buffers, falling into the sea, being pushed onto a brakevan, colliding with a cart, and being hit by a falling crate of treacle. So far, his silliest accident yet was in the sixth season, when he slipped on oily rails, crashed through the chocolate factory and emerged covered in chocolate]]. Despite this, he always tries to do his best, learn from his mistakes and get his jobs done, a loyalty which Sir Topham Hatt has praised him for on several occasions.
Although their friendship has been turbulent at times, Thomas is generally portrayed as Percy's best friend, he is also good friends with Toby as well.
Since the second season, Percy has had a small rivalry with Harold, stemming from their race. However, they are always willing to help each other when in trouble.
He also had held a grudge from the big engines about their tricking 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 Sir Topham Hatt for it.
Percy is primarily based on a Avonside 0-4-0ST with Hunslet underframes and valve gear, a smokebox protruding from his saddletank, external cylinders and motion, and sandboxes underneath the tanks on his footplate.
Modifications made to Percy's shape include the angled smokebox supports and possibly a coal bunker.
A similar looking engine painted red, lived with Percy at the Workshop where he used to live before arriving on Sodor, in the My Thomas Story Library book, The Fat Controller.
Percy is painted NWR green with NWR red-and-yellow lining and a "6" painted on his bunker sides in yellow with red lining.
In the Railway Series, he carries two builder's plates, one on either side of his cab.
- Season 100 - Geoffrey's Real, Toby and Philip (cameo), Henry the Warrior (cameo), Diesel Saves the Day, Trouble with Brakevans, Jealous James, Salty's Secret Story, The Crashing Kipper, The Lost Letters, Snowploughing at Christmas, Duncan's Dilemma (cameo), Henry in the Darkness, and Timothy and the Aquarium (cameo)
- Michael Angelis (Thomas and the Magic Railroad; original workprints only)
- Linda Ballantyne (Thomas and the Magic Railroad)
- Keith Wickham (UK; Hero of the Rails - Sodor's Legend of the Lost Treasure, excluding the nineteenth season)
- Nigel Pilkington (UK; nineteenth season onwards, excluding Sodor's Legend of the Lost Treasure)
- Martin Sherman (US; Hero of the Rails - eighteenth season)
- Christopher Ragland (US; nineteenth season onwards, UK singing voice; The Great Race)
- Chisato Nakajima (Japan; first-eighth seasons)
- Takeshi Endo (Japan; A Close Shave only)
- Chie Kōjiro (Japan; Calling All Engines! onwards)
- Anders Sundstedt (Norway; Hero of the Rails - seventeenth season, excluding King of the Railway)
- Erik Skjøld (Norway; King of the Railway and Tale of the Brave only, excluding the seventeenth season)
- Ingve Connolly Gran (Norway; eighteenth season onwards)
- Tony Marot (France and French speaking Canada; eighth season onwards)
- Mattia Nissolino (Italy)
- Eduardo Garza (Latin America; Thomas and the Magic Railroad; TV Version)
- Javier Olguín (Latin America; Hero of the Rails - The Great Race)
- Héctor Ireta de Alba (Latin America; twentieth season onwards)
- Frank Schröder (Germany; Thomas and the Magic Railroad)
- Robin Brosch (Germany; Hero of the Rails onwards)
- Achim Schülke (Germany; Audio Books only)
- Grzegorz Drojewski (Poland)
- Jarosław Domin (Poland; Samson at Your Service only)
- Reinder van der Naalt (The Netherlands)
- Yehonatan Magon (Israel)
- Troells Toya (Denmark)
- Bruno Marçal (Brazil; Hero of the Rails onwards)
- María Rubio (Spain)
- Taisto Oksanen (Finland)
- Olga Kuznetsova (Russia)
- One of Percy's models is currently on display in Japan at the Hara Model Railway Museum (previously on display at Nitrogen Studios).
- Percy is the only engine who is known to have been named by the Fat Controller.
- Percy's large scale model used for the spin-off series, The Pack, is currently on display in Japan at the Hara Model Railway Museum (previously on display at Thomas Town).
- According to Abi Grant on her website, Percy is her favourite character.
- Percy is the first character to say the infamous line "and then there was trouble."
- Percy has had three cameos in the American sit-com Everybody Loves Raymond.
- Percy's whistle sound is actually Edward and Henry's in higher pitched.
- Percy is the first character other than Thomas to be the main protagonist in a special, which he would later do again.
- Percy went through several changes in the television series:
- Season 3:
- His whistle changed shape (now being more of a cylinder shape).
- His whistle is one tone lower later in the season.
- Season 4:
- His whistle changes back to its original tone.
- In some episodes towards the end of the season, one of the two black sections extending from under his smokebox to the end of the footplate is missing.
- Thomas and the Magic Railroad:
- He gained a permanent lamp
- A stand underneath his smokebox.
- His eyebrows change shape.
- Season 6:
- His cab was blacked out (except for cab shots filmed on a larger model).
- Jack and the Sodor Construction Company (Large Scale Model Only):
- The step ladders on his running board are painted red.
- His whistle is taller than his cab.
- The Great Discovery:
- His large scale model's dome is painted gold.
- Hero of the Rails:
- His cab became open again
- The counterweights on his wheels vanished.
- Season 19:
- His side rods become silver.
- Season 3:
- Percy was featured on the 1986 single cover of Oh L'amour, a song by English synthpop duo Erasure.
- One of Percy's original face masks is owned by Twitter user ThomasTankMerch.