I'm glad someone brought this up, as I had been thinking about this a while back but forgot to post it here. DERP. Let the rambling commence. Anyway, I pretty much thought of two possibilities: 1) Each dragon has their own special breath. This may or may not be shared amongst dragons of the same type (i.e. All red dragons have smoke breath), but smoke breath or teleportation breath would special breath types themselves. 2) Spike gets magic breath because of the way he was raised. Either being raised among unicorns allowed him to pick up some sort of ambient magic OR the magic breath was actually given to him (perhaps by Celestia herself) to help him be more useful to his "Boss". This would suggest that only dragons raised in Canterlot get magic. Given that raising a dragon seems to be part of getting into magic university (or whatever they called it in the show) that would be a fair amount of dragons. To be honest I like the idea of every dragon having a different breath, just like all ponies have their own special talent. Also, just for fun I decided to come up with some random magical breath abilities. The idea for these was to come up with abilities that are useful without being overpowering. Feel free to add your own. "Bag of holding" breath. Breath on a small object to make it vanish in flames, breath again to make it reappear. Smoke breath that cleans and polishes anything it touches. Breath that doesn't burn, it merely warms and dries. Freezing breath that encases stuff in ice. Breath that the dragon can control pyrokinetically (i.e. making the breath stay in midair or circle around to follow someone). Smoke breath that turns into small lightning clouds. Breath that is actually a cloud of dust or sand (something for desert-based dragons I guess). All of these are up for grabs if anyone is applying for a dragon.