To my most faithful student, Twilight Sparkle,
In general, my dear student, it may be better to avoid racial pejoratives in all circumstances as a rule. I have found very few cases where it is appropraite to use one, and most of them were either in a classroom, or there was a great deal of violence involved and I needed a way to distract...
Well in any case, best not, Twilight.
Your loving mentor,
Princess Celestia