Hair was common, and a quarter of equestrian inhabitants had a horn. She would know, having researched it extensively. A third eye on one's forehead, however, was unheard of, and not something she would have believed possible if she hadn’t seen it for herself.
Granted, the thing had been a mistake, and helping Zecora get rid of it had taken quite a bit of doing, but the possibilities intrigued her.
Tons of coffee and an intricately designed spell later she had done it. Now if only she knew how to revive Rarity after having been exposed to her newest acquisition.