Choo Choo for backyards, preschools, day cares, and churches. Choo Choo Train Engine. You can purchase the train engine alone or make your own train set with the train car tunnelsl. The children love crawling thru the tunnels and playing engineer as well. It is a great imagination item to have on your playground. The 4 piece choo choo set include the choo choo engine, passenger car, caboose and either the water car or oil car.