The Circus Train is created using miniature versions of the larger indivudal animal pull toys. They are made from 1.5" pine stock.
 
Dimensions (width includes wheels)
Lion: 3" wide x 5" high x 6 1/2" long
Elephant: 3" wide x 6 1/2" high x 6 1/2" long
Giraffe: 3" wide x 9" high x 6" long
HIppo: 3" wide x 5" high x 7" long