Peter Sam, named after the Skarloey Railway's previous controller, Mr. Peter Sam - previously Stuart, after his builder, Kerr Stuart is a kind hearted narrow-gauge tank engine painted in dark green paint with red and yellow lining on his side tanks along with a gold number 4 on either side of his coal boxes, and lives and works on the Skarloey Railway. When he came to Sodor he use to have a normal funnel like the other narrow gauge steam engines, but after an accident at the incline, his funnel got damaged in the episode Trucks and then lost it inside a tunnel while pulling an express train as it got hit by an icicle a few episodes later in Special Funnel, which was temporarily replaced with a rusty drain pipe that his driver found on the side of the tracks when trying to finish the trip without a funnel. In no time Peter Sam's driver and fireman tied the drain pipe on to the top of Peter Sam boiler where the smoke came out. It helped Peter Sam manage the rest of the trip, but unfortunately became the laughing stock of the yard and kept getting teased by the other steam engines until eventually Peter Sam was given a new funnel, a Giesl Ejector, which suits him much better.
Peter Sam is kind, well-mannered and popular with passengers and coaches alike. Even the trucks don't play tricks on him. He is also portrayed similarly, occasionally making mistakes by feeling self-important.
- Peter Sam is one of the only engines that the troublesome trucks do not play tricks on, others being Edward, Toby, Oliver, Charlie, & Salty.
- Peter Sam's original name was Stuart.
- Peter Sam arrived to Sodor with Sir Handel.
- His Take-n-Play model does not include the 3rd window on his back.
- Take Along