Mr. Peregrine Percival, nicknamed "the Thin Controller", is the current manager of the Skarloey and Culdee Fell Railways in the television series. In the magazine stories, he also runs a Cable Railway.
Mr. Percival was hired sometime between the seventh and ninth seasons to help Sir Topham Hatt manage the ever-increasing size of the railway industry on the Island of Sodor.
He was one of the important visitors who attended Dowager Hatt's special tour of Sodor and then a party at Knapford. He later charged Peter Sam with the running of the Skarloey Railway whilst he attended a meeting with Sir Topham Hatt and welcomed Luke to his railway.
He scolded Duncan for his grumpy disposition at Christmas time. He told Duncan that he had to be cheerful all day, but later realised that demand was too hard for the grumpy engine.
He once attended a meeting with Sir Topham Hatt at Knapford, where he sparked a debate between Thomas, Spencer and Bertie over how many wheels are best, after declaring the two wheels of his bicycle were best. On the way back from the meeting, he called for help when The Duke and Duchess of Boxford needed to get to Callan Castle when Bertie was unable to take them because of a fallen tree. He later attended Sir Robert Norramby's Christmas Luncheon at Ulfstead Castle.
Mr. Percival appears to be acquainted with the Thin Clergyman, as he was seen boarding Thomas' train with him at Kellsthorpe Road, speaking to him at Vicarstown and watching the events of the Great Railway Show with him.
He was one of a group of very important passengers who went on a demonstration run of Hugo.
While Sir Topham Hatt travelled the world looking for Thomas, he left Mr. Percival in charge of the North Western Railway.
Much like Sir Topham Hatt, Peregrine is a firm but fatherly figure to the Skarloey engines and His stern, compact attitude and work ethic is only what's best for the railway.
Mr. Percival is a tall, thin gentleman. He is usually dressed in a black suit jacket with grey trousers, a yellow waistcoat, a white shirt, a black tie and a black bowler hat. He wears a pair of brown glasses.