Malakia

Malakia is a pony who hates candy and parties. She appears in "Pinkie Pie's Most Hated". She's similar to Blackfire in "Teen Titans Go". She wants to get rid of Pinkie Pie and her cutie mark (although she never actually explains why, it could probably be because she never had a cutie mark of her own)
Malakia doesn't like Pinkie Pie's friends at all. She's bossy and as bad as Starlight Glimmer in "The Cutie Map Parts 1 and 2". (If you haven't seen that episode, do so right now), The final fight is so awesome it makes you cover your eyes and ears, which will hurt really bad due to its epicness.