If you go with Chuffy (the train) to the Ice Side train station and save and quit there, Chuffy will stay there. I couldn't locate it in any Train Station, including Isle O' Hags. I played the North American version, I don't know if this occurs in the other versions of the game. I didn't need Chuffy any more, so that wasn't a problem. But in case I did, for example, if I hadn't got into Grunty Industries, this could be a game ruining bug.