Rex is a miniature green engine that works on the Chipperton and Swahilli Railway.
Rex is the confident and natural leader of the miniature railway team! Strong enough to handle the toughest goods work and friendly to all who comes to the railway, he's often the one in charge of the tougher jobs on the railway (such as heavy freights from Conifton Quarry and express passenger services to the Swahilli Waterpark Resort). He has a friendly rivalry with Mike, teasing him whenever the boastful little engine gets a little too full of himself. But it's not to be mean; it's usually to bring him back down to earth!
Rex is based on the Ravenglass and Eskdale Railway's River Esk.
Rex is painted green with red and yellow lining. He has a brass dome, brass builder's plates on the sides of his cab, red nameplates with gold writing mounted on each side of his boiler and "ARLESDALE" written on the sides of his tender in yellow.