I really thought that was Discord at first.



Hmm, when I watched the start, I was thinking that the ep should've started with a scene of Discord and RD talking, and RD mentioned that she used to prank a lot but hadn't been doing it much lately. So Discord innocently encourages her to take it up again, and also assures RD that Fluttershy is a lot stronger than RD thinks, and so pranking her would actually be fine.