My son, who at the time was turning 4, wanted a Thomas birthday. Being on a tight budget means that we make all our own cakes. I made this Thomas the Tank Engine Birthday Cake with 3 13x9 cakes and 3 8" rounds which were sliced and diced to make what you see above.
I used a photo of Thomas for a guide. I started by making a base out of 2 of the 13x9 cakes and "gluing" them together with icing in the center. The final 13x9 cake I cut about 3" off the front to make the indentation and "glued" it to the other base cakes with icing in the middle.
This piece from the front I used at the back in the next step. I took the 3 8" round cakes and cut all of them in half, essentially making 6 half-moon looking cakes. I used 2 at the back on top of the small piece I had cut from the base to make the conductor's platform in the rear. I then placed the remaining half-moons cut-side down on the base, and secured with skewers.
(As a side note - I'm not the best at making cakes stay in exactly the shape I desire, so I have found that using skewers help me hold the shape. I just give people fair warning that they are in there and we cut around - not really any different from using cake dowels. You can find skewers at any grocery store and they are usually less money than "cake supply" wooden dowels.)
Once the cake was together, I worked on the face. I used homemade fondant (recipe found on www.allrecipes.com) and worked the colors into the dough using Wilton colors and shortening on my fingers to prevent sticking. I Googled these instructions and found step-by-step instructions on making a Thomas face from fondant. I also made the smokestack out of fondant.
Once everything was ready, I did a crumb layer of icing, then used an icing bag to cover the cake with the colors I needed in each area.
(Tip - in order to make your black icing truly "black", add a small amount of cocoa powder to the icing when you put the black coloring in. It will change the taste slightly, but it will give you a solid black after it sets instead of a dark grey.)
I secured the face and smokestack with (you guessed it!) skewers. I used a large, non-floppy cookie pan covered with aluminum foil to hold and transport the cake.