As an extension to that, let's see:
None of the 11 ponies that I've created can be created in a typical pony generator. Birdie McFly's mane and position cannot, Diamond Song's scrunch face position cannot, Eliza's position and expression cannot, Beauty Brush's pose, expression, mane, and tail cannot, Amarillo's tail and glasses cannot, Stormsword's position, expression, mane, and hat cannot, Neither Pattycake nor Comet Tag can, String Plucker's build and pose cannot, Airstride's mane and pose cannot, Thorn's mane, pose, and ear piercings cannot.