Hello, I just wanted you to know I own a horse. I just changed her name to beauty
What great creatures. They have evolved from multi-toed creatures to a single hooves one. 
If you only knew. Mine has a horn between it's head and can fly. She is truly my best friend.
I'm not sure that is a horse, of all the specialized vocabulary used to describe the size, color or marking, there is not horned breed. 
I understand your worry, but I know what I have. It is quite amazing and I love her.
my son named his sisters Unicorn, "Unicorn Magic" 
What's a unicorn? I dont know anything about that.
Unicorn
The unicorn is a legendary creature that has been described since antiquity as a beast with a single large, pointed, spiraling horn projecting from its forehead. The unicorn was depicted in ancient seals of the Indus Valley Civilization and was mentioned by the ancient Greeks in accounts of natural history by various writers, including Ctesias, Strabo, Pliny the Younger, Aelian and Cosmas Indicopleustes. The Bible also describes an animal, the re'em, which some versions translate as "unicorn".
In European folklore, the unicorn is
you see something that's four-legged, you think it's a dog; that's just how we're wired ... If you make a film about an alien force, which is the oppressor or aggressor, and you don't want to empathize with them, you can go to town. So creatively that's what I wanted to do but story-wise, I just couldn't."
Blomkamp originally sought to have Weta Digital design the creatures, but the company was busy with effects for "Avatar"