Now I did say that Draco's transformation into his dragon form can either be called upon when needed, or if he becomes enraged. It turns out that trying to bring harm to Fluttershy is a surefire way to make him turn from his friendly pony form into a beast that'll try to BBQ you. Case in point, don't tick him off :P

(I do have a few pictures of Draco in dragon form, the downside is that they're all a bit inconsistent in the design department. I'll try and dig through them and upload the best one!)