Jim is a narrow gauge tank engine who used to on the Mid Sodor Railway. He was not featured in any stories, but was featured on the Rev. W. Awdry's layout of the railway. It is unknown what happened to him after the railway closed.
Jim is based on the Kerr Stuart Skylark, a class of 0-4-2 narrow gauge tank engines that were built by Kerr, Stuart and Company and worked in places such as steelworks and sugar mills. Only one of the Kerr Stuart Skylarks is still around and has been heavily modified, currently residing in a sugar mill in Mauritius on static display.
Jim is painted green with a brass dome. The top of his side tanks and footplate are painted black, and his his bufferbeam is painted red. His name and number are written on the sides of his tanks and cab respectively in yellow writing.