|Railway Series Portrait|
|Position||Goods and passenger tank engine on Thomas' Branch Line|
Since his first appearance in Desperate Measures, he broke down in the episode Tolerance with a whoosh of steam and had to be taken by Douglas to the workshop. He later joined Thomas in Night Run taking the mail to most of Sodor's towns and cities when James says that the mail run sucks and can't run on branch lines which made the two tank engines outraged. The broken drawbar Percy heard about says that James is certainly in trouble. He joined Thomas, Toby and Daisy in Snowstorm where they head a branch line special towards Knapford and by the time of Old Tricks, Percy and Thomas rejoined after falling out with each other when the blue tank engine called Percy a "klutz".
In Bluebells & Batsmen, Percy was told by Douglas that the song is daft and whistled at Stepney when he arrived at Tidmouth. Percy had appeared in other episodes following Alice's rescue by Gordon. He evenly said to Sir Charles Topham Hatt that his car was ringing from the parking lot in the episode, Rescue Mission. He took some trucks to the other side of the island when the coupling snapped and the trucks tried to make a getaway. Their mission failed when Alice's inspector stopped the train from crashing into Edward at Wellsworth station. He talks to Thomas about his new fireman in the episode, Changes. He starred in both Post & Prejudice and Bad Apple with a speaking role. In 1994, the green tank engine stopped a car with two men onboard from getting away and talked to James at Elsbridge station about the NWR's future following the bridge collapse on The Little Western.
In 2009, he was with both Thomas and Toby at Ffarquhar Sheds when Sir Stephen Topham Hatt said he's going to retire due to health problems and will appoint Norman Spencer as their acting director. The green tank engine was in three episodes of Season 1 of Sodor: The Modern Years which includes The Missing Engine, Aftermath and Homecoming.
In 2011, the mail train's schedule was rearranged; and the engines no longer took dedicated mail runs. Thomas and Oliver weren't too affected by this, but the sudden change of a schedule Percy had been used to for a while caused trouble; and Percy had difficulty starting in the morning. After having a talk with the other engines on the branch; Percy found a solution to bringing an end to these problems.
Percy is based on the GWR 1340 Trojan locomotive with the bunker of a GWR 1361 locomotive.
- Season 1 - Desperate Measures, Tolerance, The Missing Coach, Little Western (does not speak), Night Run and Snowstorm
- Season 2 - Old Tricks and Galloping Sausage (mentioned)
- Season 3 - Search Engines (does not speak), Bluebells & Batsmen, Comfort Zone (does not speak), Rescue Mission, Shakedown, Changes and Christmas Delivery (cameo)
- Season 4 - Hard Work (mentioned) and Post & Prejudice
- Barry the Rescue Engine - The Lucky Ones (cameo)
- Season 5 - A Stranger in Need, Little Western Legacy (mentioned), Doubts (cameo), Darkest Hour and Desperate Times (cameo)
- Season 1 STMY - The Missing Engine, Aftermath, Homecoming and Genesis of a Grudge (stock footage: does not speak)
- Season 2 STMY - Swan Song (cameo), Percy's Post, The Thin Clergyman, Troublesome Trucks and Endgame (cameo)
- Percy received a brand-new model based on his RWS form in Season 1 of Sodor: The Modern Years by WildNorWester.