Rusty is a small narrow gauge 0-4-0 Midlander Diesel locomotive in Thomas the Tank Engine & Friends. He is kind, helpful, faithful, friendly, and wise, has a big heart and is a best friend for life. Rusty is mostly a credit to the Skarloey Railway. He usually has problems with Duncan, who usually insults him and ignores his wise words.
Rusty's important job is maintenance work on the Skarloey Railway, providing help when he can.
In the episode "Rusty to the Rescue", he traveled to the Other Railway where he came across Stepney the Bluebell Engine. Plucking up courage, he helped Stepney to escape being scrapped and was honored for saving the engine's life.