I'm working on a level I named The Last Dragon, and would love to place the dragon from the original levels in my map. If there is a way please let me know.

Easy. All you do is load the Adventure Mode Map File in the editor, go to the room with the dragon (27) and simply use the select tool, copy it (CTRL+C) and paste it (CTRL+V) into your own room. It's shown as a floating purple box.

Hope that helps. (FYI, I'm not insulting your intelligence by over-detailing how to copy/paste it. Just thought it would be nice to go in-depth for anyone who happens to stumble upon this, wondering the same thing.)