Since I joined the MLP fandom, I made a point of trying to go with background characters for the most part rather than make up an OC.  That said, I did ponify a couple of characters that I had previously used in a D&D setting.  These are two of them.  Cacophony has gotten a bit of a makeover since the last time she appeared, and she is joined by her teacher and caretaker who calls himself Foehammer because he believes that his actual given name was somehow even more embarassing.  Cacophony got a cameo role in Sleepless Shiny’s Seaddle Sunset, and if I recall correctly she may have mentioned that she had a zebra tutor who was teaching her magic using runes or potions… her poor plushie will never be the same.