- "You have caused delay and confusion!"
- — Mr. Percival, Duncan's Bluff, tenth season
|Mr. Peregrine Percival, "the Thin Controller"
Mr. Peregrine Percival, also called the "Thin Controller" ("Narrow-Gauge Controller" in the US), is the current manager of the Skarloey and Culdee Fell Railways in the television series. In the magazines, he also runs a Cable Railway.
Mr. Percival was hired sometime between the events of the seventh and ninth seasons to help Sir Topham Hatt manage the ever-increasing size of his railway industry.
Mr. Percival has had five children with his wife.
He was one of the important visitors who attended Dowager Hatt's special tour of Sodor and then a party at Knapford.
- Season 9 - Mighty Mac, Tuneful Toots, Rheneas and the Dinosaur, Duncan and the Old Mine, and Skarloey the Brave
- Season 10 - Follow that Flour (mentioned), A Smooth Ride, Duncan Drops a Clanger (cameo), Fearless Freddie (does not speak), Duncan's Bluff, and Thomas and Skarloey's Big Day Out
- Season 11 - Thomas and the Big Bang, Duncan Does it All, Sir Handel in Charge, Cool Truckings, Ding-a-Ling, Skarloey Storms Through, and Wash Behind Your Buffers
- Season 12 - Henry Gets It Wrong (does not speak), Mountain Marvel, The Party Surprise, Duncan and the Hot Air Balloon, The Man in the Hills, and Push Me, Pull You
- Season 13 - Hiro Helps Out (mentioned)
- Season 14 - Jitters and Japes (cameo)
- Season 15 - Up, Up and Away! (cameo)
- Season 16 - Express Coming Through (cameo) and Don't Bother Victor!
- Season 17 - The Switch (mentioned)
- Mr. Percival hates cars, which explains his signature bicycle. Oddly, his Take-Along and Take-n-Play models feature him inside a red car.
- Mr. Percival's hero is Sir Topham Hatt.
Mr. Percival and his bicycle
Mr. Percival and Sir Topham Hatt in Winston
Mr. Percival in a magazine story