Bake two cake mix boxes according to directions, but use 12 lightly greased mini loaf pans instead of 2 sheet cake pans.
Allow cakes to cool completely and remove them from the loaf pans. These will serve as individual train cars.
Cut apart two of the loaves to form the shape of the engine car.
Create the train track by placing wafer cookies 1/2 inch apart in an oval shape. Sprinkle crushed chocolate cookies between the wafers as the gravel. Sprinkle coconut that has been dyed green on the inside of the track.
Line up the cars on your track one by one, using a pretzel stick for each of the connectors.
Decorate each train car with a different color icing. Put a ring of licorice string on the top of each car. Inside the ring, place various candies as "cargo".
Decorate a small round vanilla cookie to resemble Thomas's face and attach with icing to the front of the engine car. Choo choo!
Enjoy your festive and great-tasting Thomas the Tank Engine cake with all your guests!