Twist

I'm kind of surprised that Twist never had another speaking part after her first appearance, but at least she became a regular background filly in the CMC class scenes (unlike poor Pipsqueak, who seemed to vanish from Ponyville until finally making a brief background showing again.) Not that I really imagine there's a lot of story left to tell with Twist... it just seemed like she was likely to be a more important character in those days before the CMC were firmly established. But once she got her cutie mark, Apple Bloom dropped her faster than if she had declared pears the best fruit imaginable.