- “When I was a baby horse, Mama told me the day will come when I will be called upon to fulfill a responsibility greater than myself, greater than this dimension. For me, that day is today!”
- ―Vincenzo (speaking Italian)[src]
First Millhorse (Pumpkin)
When healthy, Pumpkin has a white coat, starry pink mane and tail, green horn, and a heart on her chest. The head is similar to Pony Head's. When tired, she becomes thin and ragged, her coat is mostly grey, her mane, tail, and horn darken, and her mane and tail go limp, while the heart on her chest looks broken.
Second Millhorse (Vincenzo)
At the end of "Storm the Castle," Pumpkin is replaced by Vincenzo as part of fulfilling its "responsibility." Vincenzo is more mature-looking and has a gray coat, a greenish-gray mane which he pulls back into a ponytail, a dark blue shirt, yellow and black bands around his hooves, and a detachable horn. Vincenzo is notable in that he speaks fluent Italian.
Third Millhorse (Firstborn)
Near the end of "Toffee", Star used the last remaining piece of magic in the universe that has not been corrupted by Toffee to give birth to a third Millhorse. Much younger than the previous two, this Millhorse has a white coat, a dark blue mane, a yellow horn, and a gold butterfly-shaped mark on its haunches. By "Deep Dive", this Millhorse has grown to the size of an adult mare, and the other unicorns in the Realm of Magic refer to her as the "Firstborn".
In "Cleaved", it is revealed that the Firstborn was killed by the Dark Millhorse, and her soul is later released from the Royal Magic Wand when Star, Moon, Eclipsa, and Meteora used the Whispering Spell to destroy magic.
- Bartholomew the Brave (served Lyric, Skywynne, and Solaria Butterfly)
- Orion the Brindle (served Eclipsa Butterfly)
- Stephandipity (served Festivia Butterfly)
- Chastity (served Dirhhennia, Crescenta, and Rhina Butterfly)
- Ghost (served Rhina, Celena, and Estrella Butterfly)
- Ogilvie the Third (served Rhina Butterfly)
- Torento (served Rhina Butterfly)
- Blossom (served Rhina Butterfly)
- Pumpkin (served Comet, Moon, and Star Butterfly)
- Vincenzo (served Star Butterfly)
- The Firstborn (served Star, Eclipsa, Moon and Marco)
- Dark Millhorse
In the Realm of Magic, it is shown that there are at least seven smaller unicorns other than The Firstborn.
- ↑ Star and Marco's Guide to Mastering Every Dimension by Dominic Bisignano and Amber Benson. March 7, 2017. Published by Disney Press. Page(s) 191. ISBN: 978-1484774199.