Neil is a dark green tank engine with an unusual box shape and a Scottish accent. He is a simple but kind engine, who befriended Skarloey when he was young.
Neil is based on a Neilson 0-4-0 box tank, a simple and robust class of engine built in Glasgow and sold all over the world. This basis is reflected in his name and class. His country of origin also explains his accent.
Neil is painted dark green with "S & M 2" written on his tank sides in yellow.