Arthur is a tank engine who runs the Norramby Branch Line.
Arthur took great pride in his spotless record, which he soon lost after colliding with Duck's trucks in an incident largely provoked by Thomas. However, this spotless record was soon amended, after Thomas apologized to him for causing the accident.
He was bought to shunt and pull goods, but then was transferred to the coastal run, on which he enjoys working. He is responsible for this line, which is famous for its fish. Arthur is the only known engine to enjoy the smell of fish.