For my great-nephew who had to have a particular type of train. I found the train image on the web, and printed and laminated it to set in front of the cake like it was coming out of the tunnel. I don’t usually put non-edible items on cakes, but I just didn’t have the time (or the talent) for all the detail that train required.
His grandmother suggested the name and number made to look like train tracks. I thought they turned out pretty cute.