Percy is a little green saddle tank engine who lives and works on the Island of Sodor, and is the North Western Railway's number 6 engine. He was first brought to Sodor to help run the railway while Gordon, James and Henry went on strike and later became station pilot at Knapford. Following the renovation of New Harbour, Percy was moved permanently to Thomas' Branch Line, where he now works as a goods engine. His favorite job is pulling the Mail Train and he is Thomas' best friend.