I do believe that John Allen on his Gorre and Daphetid called it a 0-4-0 since it has 4 driving wheels and no idler wheels. It could also be called a 0-2-2-0 I guess. I do know that it was locomotive 13 and was an "Organic Switcher" named Emma the stegosaurus. One of the greatest model railroads of all time.
I'm gonna have to find a model for that now in N scale. My great-niece Emma is all excited about the railroad and is going to help me with it. Which is good, as she is very artistic!
Reminds me of the "steam shovel" Fred Flintstone operated... Would make a nice quarry scene. Yabba dabba do!