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Now that I have answered that question, let me add one last thing. Magic is not a toy, and sometimes it can be downright dangerous. Untrained manipulation of a ponys natural magic can result in permanent, irreversible damage.
 
And before you ask, there are plenty of advanced gardening classes or advanced body building that deal with enhancement of earth pony magic (not that they call it that), if youre interested in that. There are no pegasus magic classes currently, as it seems the pegasus culture has something against the concept of messing with their magic. Im currently working on a side project in that regard, though.